Devices and methods for performing a vascular anastomosis

ABSTRACT

A system for performing an end-to-side vascular anastomosis, including an anastomosis device, an application instrument and methods for performing a vascular anastomosis. The system is applicable for performing an anastomosis between a vascular graft and the ascending aorta in coronary artery bypass surgery, particularly in port-access CABG surgery. A first aspect of the invention includes a vascular anastomosis staple. A first configuration has two parts: an anchor member, forming the attachment with the target vessel wall and a coupling member, forming the attachment with the bypass graft vessel. The anastomosis is completed by inserting the coupling member, with the graft vessel attached, into the anchor member. A second configuration combines the functions of the anchor member and the coupling member into a one-piece anastomosis staple. A second aspect of the invention includes an anastomotic fitting, having an inner flange over which the graft vessel is everted and an outer flange which contacts the exterior surface of the target vessel. A tailored amount of compression applied by the inner and outer flanges grips the target vessel wall and creates a leak-proof seal between the graft vessel and the target vessel. A third aspect of the invention has a flange to which the graft vessel attaches, by everting the graft vessel over the flange, and a plurality of staple-like members which attach the flange and the everted end of the graft vessel to the wall of the target vessel to form the anastomosis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/916,012, filed Jul. 26, 2001, now abandoned, which is a division ofU.S. patent application Ser. No. 09/756,355, filed Jan. 8, 2001, nowissued as U.S. Pat. No. 6,443,965, which is a continuation of U.S.patent application Ser. No. 09/315,365, filed May 18, 1999, now issuedas U.S. Pat. No. 6,171,321, which is a continuation of application Ser.No. 09/166,338, filed Oct. 5, 1998, now issued as U.S. Pat. No.5,904,697, which is a divisional of Ser. No. 08/789,327, filed Jan. 23,1997, now issued as U.S. Pat. No. 5,817,113, which is a divisional ofapplication Ser. No. 08/394,333, filed Feb. 24, 1995, now issued as U.S.Pat. No. 5,695,504. The complete disclosures of the aforementionedrelated U.S. patent applications are hereby incorporated herein byreferenced for all purposes.

FIELD OF INVENTION

The present invention relates generally to devices and methods forsurgically performing an end-to-side anastomosis of hollow organs. Moreparticularly, it relates to vascular anastomosis devices for joining theend of a graft vessel, such as a coronary bypass graft, to the side wallof a target vessel, such as the aorta or a coronary artery.

BACKGROUND OF THE INVENTION

Anastomosis is the surgical joining of biological tissues, especiallythe joining of tubular organs to create an intercommunication betweenthem. Vascular surgery often involves creating an anastomosis betweenblood vessels or between a blood vessel and a vascular graft to createor restore a blood flow path to essential tissues. Coronary arterybypass graft surgery (CABG) is a surgical procedure to restore bloodflow to ischemic heart muscle whose blood supply has been compromised byocclusion or stenosis of one or more of the coronary arteries. Onemethod for performing CABG surgery involves harvesting a saphenous veinor other venous or arterial conduit from elsewhere in the body, or usingan artificial conduit, such as one made of Dacron or Goretex tubing, andconnecting this conduit as a bypass graft from a viable artery, such asthe aorta, to the coronary artery downstream of the blockage ornarrowing. A graft with both the proximal and distal ends of the graftdetached is known as a “free graft”. A second method involves reroutinga less essential artery, such as the internal mammary artery, from itsnative location so that it may be connected to the coronary arterydownstream of the blockage. The proximal end of the graft vessel remainsattached in its native position. This type of graft is known as a“pedicled graft”. In the first case, the bypass graft must be attachedto the native arteries by an end-to-side anastomosis at both theproximal and distal ends of the graft. In the second technique at leastone end-to-side anastomosis must be made at the distal end of the arteryused for the bypass. In the description below we will refer to theanastomoses on a free graft as the proximal anastomosis and the distalanastomosis. A proximal anastomosis is an anastomosis on the end of thegraft vessel connected to a source of blood (e.g. the aorta) and adistal anastomosis is an anastomosis on the end of the graft vesselconnected to the destination of the blood flowing through it (e.g. acoronary artery). The anastomoses will also sometimes be called thefirst anastomosis or second anastomosis, which refers to the order inwhich the anastomoses are performed regardless of whether theanastomosis is on the proximal or distal end of the graft.

At present, essentially all vascular anastomoses are performed byconventional hand suturing. Suturing the anastomoses is a time-consumingand difficult task, requiring much skill and practice on the part of thesurgeon. It is important that each anastomosis provide a smooth, openflow path for the blood and that the attachment be completely free ofleaks. A completely leak-free seal is not always achieved on the veryfirst try. Consequently, there is a frequent need for resuturing of theanastomosis to close any leaks that are detected.

The time consuming nature of hand sutured anastomoses is of specialconcern in CABG surgery for several reasons. Firstly, the patient isrequired to be supported on cardiopulmonary bypass (CPB) for most of thesurgical procedure, the heart must be isolated from the systemiccirculation (i.e. “cross-clamped”), and the heart must usually bestopped, typically by infusion of cold cardioplegia solution, so thatthe anastomosis site on the heart is still and blood-free during thesuturing of the anastomosis. CPB, circulatory isolation and cardiacarrest are inherently very traumatic, and it has been found that thefrequency of certain post-surgical complications varies directly withthe duration for which the heart is under cardioplegic arrest(frequently referred to as the “crossclamp time”). Secondly, because ofthe high cost of cardiac operating room time, any prolongation of thesurgical procedure can significantly increase the cost of the bypassoperation to the hospital and to the patient. Thus, it is desirable toreduce the duration of the crossclamp time and of the entire surgery byexpediting the anastomosis procedure without reducing the quality oreffectiveness of the anastomoses.

The already high degree of manual skill required for conventionalmanually sutured anastomoses is even more elevated for closed-chest orport-access thoracoscopic bypass surgery, a newly developed surgicalprocedure designed to reduce the morbidity of CABG surgery as comparedto the standard open-chest CABG procedure. This procedure is more fullydescribed in commonly-assigned, U.S. Pat. No. 5,452,733, issued Sep. 26,1995 and U.S. Pat. No. 5,735,290, issued Apr. 7, 1998, the completedisclosures of which are hereby incorporated by reference. In theclosed-chest procedure, surgical access to the heart is made throughnarrow access ports made in the intercostal spaces of the patient'schest, and the procedure is performed under thoracoscopic observation.Because the patient's chest is not opened, the suturing of theanastomoses must be performed at some distance, using elongatedinstruments positioned through the access ports for approximating thetissues and for holding and manipulating the needles and sutures used tomake the anastomoses. This requires even greater manual skill than thealready difficult procedure of suturing anastomoses during open-chestCABG surgery.

In order to reduce the difficulty of creating the vascular anastomosesduring either open or closed-chest CABG surgery, it would be desirableto provide a rapid means for making a reliable end-to-side anastomosisbetween a bypass graft or artery and the aorta or the native vessels ofthe heart. A first approach to expediting and improving anastomosisprocedures has been through stapling technology. Stapling technology hasbeen successfully employed in many different areas of surgery for makingtissue attachments faster and more reliably. The greatest progress instapling technology has been in the area of gastrointestinal surgery.Various surgical stapling instruments have been developed forend-to-end, side-to-side, and end-to-side anastomoses of hollow ortubular organs, such as the bowel. These instruments, unfortunately, arenot easily adaptable for use in creating vascular anastomoses. This ispartially due to the difficulty in miniaturizing the instruments to makethem suitable for smaller organs such as blood vessels. Possibly evenmore important is the necessity of providing a smooth, open flow pathfor the blood. Known gastrointestinal stapling instruments forend-to-side or end-to-end anastomosis of tubular organs are designed tocreate an inverted anastomosis, that is, one where the tissue foldsinward into the lumen of the organ that is being attached. This isacceptable in gastrointestinal surgery, where it is most important toapproximate the outer layers of the intestinal tract (the serosa). Thisis the tissue which grows together to form a strong, permanentconnection. However, in vascular surgery this geometry is unacceptablefor several reasons. Firstly, the inverted vessel walls would cause adisruption in the blood flow. This could cause decreased flow andischemia downstream of the disruption, or, worse yet, the flowdisruption or eddies created could become a locus for thrombosis whichcould shed emboli or occlude the vessel at the anastomosis site.Secondly, unlike the intestinal tract, the outer surfaces of the bloodvessels (the adventitia) will not grow together when approximated. Thesutures, staples, or other joining device may therefore be neededpermanently to maintain the structural integrity of the vascularanastomosis. Thirdly, to establish a permanent, nonthrombogenic vessel,the innermost layer (the endothelium) should grow together for acontinuous, uninterrupted lining of the entire vessel. Thus, it would bepreferable to have a stapling instrument that would create vascularanastomoses that are everted, that is folded outward, or which createdirect edge-to-edge coaptation without inversion.

At least one stapling instrument has been applied to performing vascularanastomoses during CABG surgery. This device, first adapted for use inCABG surgery by Dr. Vasilii I. Kolesov and later refined by Dr. EvgeniiV. Kolesov (U.S. Pat. No. 4,350,160), was used to create an end-to-endanastomosis between the internal mammary artery (IMA) or a vein graftand one of the coronary arteries, primarily the left anterior descendingcoronary artery (LAD). Because the device could only perform end-to-endanastomoses, the coronary artery first had to be severed and dissectedfrom the surrounding myocardium, and the exposed end everted forattachment. This technique limited the indications of the device tocases where the coronary artery was totally occluded, and thereforethere was no loss of blood flow by completely severing the coronaryartery downstream of the blockage to make the anastomosis. Consequently,this device is not applicable where the coronary artery is onlypartially occluded and is not at all applicable to making the proximalside-to-side anastomosis between a bypass graft and the aorta.

One attempt to provide a vascular stapling device for end-to-sidevascular anastomoses is described in U.S. Pat. No. 5,234,447, granted toKaster et al, for a Side-to-end Vascular Anastomotic Staple Apparatus.Kaster et al, provide a ring-shaped staple with staple legs extendingfrom the proximal and distal ends of the ring to join two blood vesselstogether in an end-to-side anastomosis. However, this device falls shortof fulfilling the desired objectives of the present invention.Specifically, Kaster does not provide a complete system for quickly andautomatically performing an anastomosis. The method of applying theanastomosis staple disclosed by Kaster involves a great deal of manualmanipulation of the staple, using hand operated tools to individuallydeform the distal tines of the staple after the graft has been attachedand before it is inserted into the opening made in the aortic wall. Oneof the more difficult maneuvers in applying the Kaster staple involvescarefully everting the graft vessel over the sharpened ends of thestaple legs, then piercing the everted edge of the vessel with thestaple legs. Experimental attempts to apply this technique have provento be very problematic because of difficulty in manipulating the graftvessel and the potential for damage to the graft vessel wall. For speed,reliability and convenience, it is preferable to avoid the need forcomplex maneuvers while performing the anastomosis. Further bendingoperations must then be performed on the staple legs. Once the distaltines of the staple have been deformed, it may be difficult to insertthe staple through the aortotomy opening. Another disadvantage of theKaster device is that the distal tines of the staple pierce the wall ofthe graft vessel at the point where it is everted over the staple.Piercing the wall of the graft vessel potentially invites leaking of theanastomosis and may compromise the structural integrity of the graftvessel wall, serving as a locus for a dissection or even a tear whichcould lead to catastrophic failure. Because the Kaster staple legs onlyapply pressure to the anastomosis at selected points, there is apotential for leaks between the staple legs. The distal tines of thestaple are also exposed to the blood flow path at the anastomotic sitewhere it is most critical to avoid the potential for thrombosis. Thereis also the potential that exposure of the medial layers of the graftvessel where the staple pierces the wall could be a site for the onsetof intimal hyperplasia, which would compromise the long-term patency ofthe graft. Because of these potential drawbacks, it is desirable to makethe attachment to the graft vessel as atraumatic to the vessel wall aspossible and to eliminate as much as possible the exposure of anyforeign materials or any vessel layers other than a smooth uninterruptedintimal layer within the anastomosis site or within the graft vessellumen.

A second approach to expediting and improving anastomosis procedures isthrough the use of anastomotic fittings for joining blood vesselstogether. One attempt to provide a vascular anastomotic fitting devicefor end-to-side vascular anastomoses is described in U.S. Pat. No.4,366,819, granted to Kaster for an Anastomotic Fitting. This device isa four-part anastomotic fitting having a tubular member over which thegraft vessel is everted, a ring flange which engages the aortic wallfrom within the aortic lumen, and a fixation ring and a locking ringwhich engage the exterior of the aortic wall. Another similarAnastomotic Fitting is described in U.S. Pat. No. 4,368,736, alsogranted to Kaster. This device is a tubular fitting with a flangeddistal end that fastens to the aortic wall with an attachment ring, anda proximal end with a graft fixation collar for attaching to the graftvessel. These devices have a number of drawbacks that the presentinvention seeks to overcome. Firstly, the anastomotic fittings describedexpose the foreign material of the anastomotic device to the blood flowpath within the arteries. This is undesirable because foreign materialswithin the blood flow path can have a tendency to cause demolysis,platelet deposition and thrombosis. Immune responses to foreignmaterial, such as rejection of the foreign material or auto-immuneresponses triggered by the presence of foreign material, tend to bestronger when the material is exposed to the bloodstream. As such, it ispreferable that as much as possible of the interior surfaces of ananastomotic fitting that will be exposed to the blood flow path becovered with vascular tissue, either from the target vessel or from thegraft vessel, so that a smooth, continuous, hemocompatible endotheliallayer will be presented to the bloodstream. The anastomotic fittingdescribed by Kaster in the 819 patent also has the potential drawbackthat the spikes that hold the graft vessel onto the anastomotic fittingare very close to the blood flow path, potentially causing trauma to theblood vessel that could lead to leaks in the anastomosis or compromiseof the mechanical integrity of the vessels. Consequently, it isdesirable to provide an anastomosis fitting that is as atraumatic to thegraft vessel as possible. Any sharp features such as attachment spikesshould be placed as far away from the blood flow path and theanastomosis site as possible so that there is no compromise of theanastomosis seal or the structural integrity of the vessels.

Another device, the 3M-Unilink device for end-to-end anastomosis (U.S.Pat. Nos. 4,624,257; 4,917,090; 4,917,091) is designed for use inmicrosurgery, such as for reattaching vessels severed in accidents. Thisdevice provides an anastomosis clamp that has two eversion rings whichare locked together by a series of impaling spikes on their opposingfaces. However, this device is awkward for use in end-to-sideanastomosis and tends to deform the target vessel; therefore it is notcurrently used in CABG surgery. Due to the delicate process needed toinsert the vessels into the device, it would also be unsuitable forport-access surgery.

In order to solve these and other problems, it is desirable to providean anastomosis device which performs an end-to-side anastomosis betweenblood vessels or other hollow organs and vessels. It is also desirableto provide an anastomosis device which minimizes the trauma to the bloodvessels while performing the anastomosis, which minimizes the amount offoreign materials exposed to the blood flow path within the bloodvessels and which avoids leakage problems, and which promotes rapidendothelialization and healing. Further, it would be desirable toprovide such a device which could be used in port-access CABG surgery.Whether it is used with open-chest or closed-chest surgical techniques,it is also desirable that the invention provide a complete system forquickly and automatically performing an anastomosis with a minimalamount of manual manipulation.

SUMMARY OF THE INVENTION

In keeping with the foregoing discussion, the present invention providesan anastomosis system for quickly and reliably performing an end-to-sidevascular anastomosis. The anastomosis system includes an anastomosisdevice, an application instrument and methods for their use inperforming an end-to-side vascular anastomosis. The system is especiallyuseful for performing an anastomosis between a vascular graft and thewall of the ascending aorta in CABG surgery, particularly in port-accessCABG surgery. One desirable attribute of the anastomosis system is thatthe system should be as atraumatic as possible to the graft vessel increating the anastomosis. Another desirable attribute of the anastomosissystem is that the anastomosis device should minimize the amount offoreign material exposed to the blood flow path in the completedanastomosis. The anastomosis device of the system has a generallytubular or ring-shaped body having a proximal end and a distal end. Anorifice or internal lumen in the body allows the graft vessel to passthrough the device from the proximal end to the distal end. The body ofthe device has an attachment means at the distal end for attachment tothe graft vessel, generally by everting the graft vessel over theattachment means. Means are provided for attaching the device and thegraft vessel to the wall of the target vessel. Different embodiments ofthe anastomosis device are presented which vary in the form of the meansused for attaching to the graft vessel and the target vessel.

A first aspect of the present invention takes the form of a vascularanastomosis staple device which may be used as part of an overallanastomosis stapling system and method designed to efficiently andreliably perform an end-to-side anastomosis between a graft vessel andthe wall of a target vessel. The anastomosis staple device forms anatraumatic attachment to the end of the graft vessel so that only asmooth uninterrupted layer of intimal cells is exposed at theanastomosis site or within the graft vessel lumen. The anastomosisstaple device creates a firm, reliable attachment between the graftvessel and the target vessel wall, with a tailored amount of tissuecompression applied at the anastomosis site to form a leak-proof jointbetween the graft vessel and the target vessel wall. The anastomosisstapling system is designed to combine the various functions of graftvessel preparation, target vessel preparation, vessel approximation andanastomosis stapling into an integrated system of instruments so thatthe anastomosis can be performed efficiently with a minimum of manualmanipulation of the vessels or the instruments involved. Differentembodiments of the anastomosis stapling system are provided to meet theneeds of performing either a first anastomosis or a second anastomosisof a bypass procedure. The anastomosis stapling system is configured tobe adaptable for closed-chest or port-access CABG surgery or for moreconventional open-chest CABG surgery.

In one preferred configuration of the invention, the anastomosis stapledevice consists of two parts: an anchor member and a coupling member.The anchor member forms the attachment with the target vessel wall. Thecoupling member separately forms the attachment with the bypass graftvessel. The complete anastomosis is created when the coupling member,with the graft vessel attached, is inserted into the anchor member. In asecond preferred configuration of the invention, the anastomosis stapledevice combines the functions of the anchor member and the couplingmember into a single member. A one-piece anastomosis staple deviceattaches to both the target vessel wall and the graft vessel to form acomplete end-to-side anastomosis. In all embodiments of the anastomosisstaple device, certain desirable aspects are maintained, specificallythe atraumatic attachment of the device to the graft vessel and therapid, reliable formation of the anastomosis, as well as theadaptability of the staple device to port-access CABG surgery.

A second aspect of the present invention takes the form of ananastomotic fitting for attaching the end of a graft vessel to anopening formed in the side wall of a target vessel. The anastomoticfitting has an inner flange which provides an atraumatic attachment forthe everted end of a graft vessel. The inner flange is configured sothat, wherever possible, a smooth, continuous, uninterrupted layer ofintimal tissue lines the graft vessel, the target vessel and theanastomotic site, with as little foreign material as possible exposed tothe blood flow path. The outer flange contacts the exterior surface ofthe target vessel. A locking means, which may be part of the outerflange, locks the outer flange in a fixed position relative to the innerflange. The inner flange, in combination with the outer flange, providesa firm attachment to the target vessel wall. A tailored amount ofcompression applied by the inner and outer flanges grips the targetvessel wall and creates a leak-proof seal between the graft vessel andthe target vessel. Optionally, attachment spikes on the surfaces ofeither the inner or, the outer flange provide additional grip on thegraft vessel and/or the target vessel. The attachment spikes areisolated from the blood flow lumens of the graft vessel and the targetvessel so that they do not compromise the anastomotic seal or thestructural integrity of the anastomotic attachment.

In a first representative embodiment, the anastomotic fitting is made upof two coacting parts: a) a tubular inner sleeve, which has an internallumen of sufficient size to accommodate the external diameter of thegraft vessel and an inner flange which is attached at the distal end ofthe inner sleeve, and b) an outer flange which has a central orificethat is sized to fit over the exterior of the inner sleeve. Anadjustable locking mechanism holds the outer flange on the inner sleeveat a selected position to create a tailored degree of tissue compressionat the anastomotic site.

The anastomosis procedure is performed by passing the end of the graftvessel through the inner lumen of the inner sleeve until the end of thevessel extends a short distance from the distal end of the sleeve. Theend of the graft vessel is then everted over the inner flange of thefitting to form an atraumatic attachment. A loop of suture or spikes onthe outside of the inner sleeve or flange may be added to help retainthe graft vessel in its everted position. The inner flange and theeverted end of the graft vessel are then passed through an opening thathas previously been made in the wall of the target vessel with aninstrument such as an aortic punch. The opening must stretch slightly toallow the inner flange to pass through. The elastic recovery of thetarget vessel wall around the opening helps to create an anastomoticseal by contracting around the inner sleeve and the everted graft vesselwall. The outer flange is then slid onto the proximal end of the innersleeve. If the anastomosis being performed is the first anastomosis on afree graft, such as a saphenous vein graft, then the outer flange can beslid over the graft vessel from the free end. If the other end of thegraft vessel is not free, such as when performing the second anastomosisof a free graft or a distal anastomosis on a pedicled graft like theIMA, then the outer flange should be back loaded onto the graft vesselor preloaded onto the proximal end of the inner sleeve before the end ofthe graft vessel is attached to the inner flange of the fitting. Theouter flange is slid down the inner sleeve until it contacts theexterior wall of the target vessel. A tailored amount of compression isapplied to the anastomosis and the locking mechanism is engaged tocomplete the anastomosis.

A second representative embodiment of the anastomotic fitting has anexpanding inner flange which facilitates the atraumatic attachment ofthe graft vessel to the fitting and makes it easier to pass the innerflange and the everted graft vessel through the opening in the targetvessel wall. The graft vessel is passed through an internal lumen of aninner sleeve which has the expandable inner flange attached at itsdistal end. The end of the graft vessel is everted over the unexpandedinner flange. The inner flange and the everted end of the graft vesselare passed through the opening in the target vessel wall. Once the innerflange of the fitting is in the lumen of the target vessel, it isexpanded to a diameter which is significantly larger than the opening inthe target vessel wall. Then an outer flange is applied and locked intoa selected position on the inner sleeve as described above to completethe anastomosis.

Different mechanisms are disclosed to accomplish the expansion of theinner flange. In a first variant of the expanding inner flange, theflange and a portion of the inner sleeve are slotted to create multiplefingers which are initially collapsed inward toward the center of thesleeve. A second inner sleeve is slidably received within the slottedinner sleeve. The graft vessel is inserted through the internal lumen ofboth sleeves and everted over the collapsed fingers of the flange. Thecollapsed flange is inserted through the opening in the target vessel.Then, the second inner sleeve is slid distally within the slotted innersleeve. The second inner sleeve forces the fingers outward, expandingthe flange within the target vessel. The anastomosis is completed byapplying the outer flange to the fitting as described above.

A second variant of the expanding inner flange has a slotted innersleeve with multiple fingers that are oriented essentiallylongitudinally to the inner sleeve. Each of the fingers has a bend in itto predispose it to bend outward at the middle when under longitudinalcompression. A tubular forming tool slidably received within the slottedsleeve is crenellated with multiple radially extending tabs. Theradially extending tabs engage the distal ends of the fingers of theslotted inner sleeve. The anastomosis is performed by passing, the graftvessel through the internal lumen of the fitting and everting it overthe fingers. If desired, a loop of suture can be used to hold theeverted vessel in place. The fingers of the fitting and the everted endof the graft vessel are inserted through an opening in the target vesselwall. When the tubular forming tool is slid proximally with respect tothe slotted inner sleeve, the radially extending tabs bear against thedistal ends of the fingers, compressing them longitudinally. The fingersbow outward, folding at the bend to expand and create an inner flangewhich engages the inner surface of the target vessel wall. In apreferred embodiment of this variation, the slotted inner sleeve has aproximal collar which captures the outer flange of the fitting so thatthe outer flange is applied simultaneously with the expansion of theinner flange. After the inner flange has been expanded, the tubularforming tool can be removed by rotating it with respect to the slottedinner sleeve so that the tabs align with the slots allowing it to bewithdrawn from the fitting. This reduces the mass of foreign materialthat is left as an implant at the anastomotic site.

A third representative embodiment is a one-piece anastomotic fittingwith an inner sleeve that is integrally attached to a fixed inner flangeand to a deformable outer flange. The anastomosis is performed bypassing the graft vessel through the internal lumen of the inner sleeveand everting it over the inner flange. The inner flange and the evertedend of the graft vessel are inserted through an opening in the wall ofthe target vessel. Then, the outer flange is deformed against theexterior surface of the target vessel wall with a tailored degree oftissue compression to complete the anastomosis. Two variants of thedeformable outer flange are disclosed. The first variant has an outerflange that is divided into flange segments. The flange segments areattached to the inner sleeve by deformable hinges. The second varianthas an outer flange in the form of a deformable hollow body. The hollowbody is deformed against the exterior surface of the target vessel tocomplete the anastomosis.

The vascular anastomotic fitting is also part of a complete anastomosissystem which includes instruments for applying the anastomosis fittingin a rapid, efficient and reliable manner to expedite the anastomosisprocess and to reduce the amount of manual manipulation necessary toperform the anastomosis. The application instrument has an elongatedbody with means at the distal end for grasping the anastomosis fittingand inserting the fitting into the chest cavity of a patient through anaccess port. The instrument includes an actuating means for deployingthe inner and/or outer flange of the fitting to create the anastomosis.Variants of the instrument are specially adapted for each differentembodiment and subvariation of the anastomosis fitting.

A third approach to expediting and improving anastomosis procedures usedby the present invention combines the advantages of surgical staplingtechnology with other advantages of anastomotic fittings. Surgicalstapling technology has the potential to improve anastomosis proceduresover hand suturing techniques by decreasing the difficulty andcomplexity of the manipulations necessary and by increasing the speedand reliability of creating the anastomosis. The Kaster vascular staplein U.S. Pat. No. 5,234,447 overcomes one of the major limitations of theprevious Kolesov stapling device by allowing a stapled end-to-sideanastomosis. This device, however, requires many delicate manualmanipulations of the graft vessel and the staple while performing theanastomosis. This device therefore does not take full advantage of thetime saving potential usually associated with stapling techniques.

The present invention attempts to marry the advantages of staplingapproaches and anastomotic fitting approaches while carefully avoidingtheir potential drawbacks. As such. the present invention takes fulladvantage of the speed and reliability of stapling techniques, avoidinginasmuch as possible the need for complex manual manipulations. Theinvention also profits from the advantages of anastomotic fittings byproviding a ring or flange that exerts even pressure around theanastomotic interface to eliminate potential leaks between the stapledattachments. The ring or flange also serves as a stent or support forthe anastomosis site to prevent acute or long-term closure of theanastomosis. Inasmuch as possible the bulk of the fitting is kept on theexterior of the anastomosis so as to eliminate exposed foreign materialin the bloodstream of the graft vessel or the target vessel. In mostcases, only the narrow staple leas penetrate the anastomosis site, sothat an absolute minimum of foreign material is exposed to the bloodflow path, on the same order as the mass of suture exposed in a standardsutured anastomosis. The attachment technique for the anastomosis deviceeliminates the need to evert the graft vessel over a complex, irregularor sharp object such as the sharpened ends of the staple legs. Instead,a smooth ring or flange surface is provided for everting the graftvessel without damage or undue complication. The staple legs areseparate or recessed within the flange to avoid potential damage to thegraft vessel while attaching it to the device.

In a third aspect, the present invention takes the form of ananastomosis device which has a ring or flange to which the graft vesselattaches, typically by everting the graft vessel over the distal end ofthe ring. The ring or flange resides on the exterior of the graft vesselso that it does not contact the blood flow path. A plurality ofstaple-like members attach the ring and the everted end of the graftvessel to the wall of the target vessel, which may be the aorta, acoronary artery or other vessel. An opening is created in the targetvessel wall with an aortic punch or similar instrument to allow thetarget vessel lumen to communicate with the graft vessel lumen. Theopening in the target vessel wall can be made before or after the devicehas been attached, depending on the application technique employed. Inmost of the examples disclosed, the staple members pierce the evertedwall of the graft vessel and the wall of the target vessel to hold thetwo vessels together. Alternatively, the staple members may enter thelumen of the target vessel through the opening in the wall and thenpierce the wall of the target vessel in the reverse direction. Thisvariation pins together the vascular layers in the target vessel at thecut edge, potentially reducing the incidence of hemodynamicallygenerated dissections in the wall of the target vessel.

Various configurations of the invention are disclosed which all exhibitthe unifying characteristics of a cooperating ring or flange and aplurality of staple members. A first exemplary embodiment includes aring-like fastening flange with deformable staple members for attachingthe flange. A specially adapted staple applying device which operatesthrough the lumen of the graft vessel is used to deform the staples tocomplete the anastomosis. A second embodiment includes a ring-likefastening flange with preformed, spring-like staple members. The elasticmemory of the spring-like staple members holds the anastomosis tightlytogether. A family of embodiments includes a tubular fastening flangewith U-shaped staple members and a locking means for fastening thestaple members to complete the anastomosis. Another family ofembodiments includes one or more ring-shaped fastening flanges withintegrally formed staple members. Another family of embodiments includesa ring-like fastening flange with self-deploying staple members made ofa superelastic metal alloy or a thermally activated shape-memory alloy.A specially adapted staple applying device deploys the superelasticstaple members. The specially adapted staple applying device togetherwith the anastomosis device itself forms a total anastomosis system thatis adaptable for either conventional open-chest CABG surgery orport-access CABG surgery.

Catheter devices are described which can be used as part of the totalanastomosis system for isolating a portion of the target artery tofacilitate performing the anastomosis procedure. One catheter device isconfigured to isolate a portion of the ascending aorta wall withoutoccluding blood flow through the lumen of the aorta. A second catheterdevice is configured to be delivered by a transluminal approach forisolating a portion of a coronary artery during the anastomosisprocedure. A third catheter device is configured to be delivered throughthe lumen of the graft vessel for isolating a portion of a coronaryartery during the anastomosis procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the anchor member and the couplingmember of a two-piece embodiment of the anastomosis staple device of thepresent invention.

FIG. 2 is a perspective view of a staple applier system for applying theanastomosis staple device of FIG. 1.

FIG. 3 is a perspective view of the distal end of the staple appliersystem of FIG. 2 showing the stapling mechanism and the vessel punchmechanism along with the anchor member of the two-piece anastomosisstaple device of FIG. 1.

FIG. 4 is a cross sectional view of the distal ends of the staplingmechanism and the vessel punch mechanism of the staple applier system ofFIG. 2 along with the anchor member of the two-piece anastomosis stapledevice of FIG. 1.

FIGS. 5A-5G are side cross section view showing the sequence ofoperations for creating an end-to-side anastomosis with the two-pieceanastomosis staple device of FIG. 1.

FIG. 6A is a perspective view of the graft insertion tool of theanastomosis staple applier system of FIG. 2 prepared for insertion ofthe bypass graft with the coupling member of the two-piece anastomosisstaple device. FIGS. 6B-6C are side cross section and perspective views,respectively, of the distal end of the graft insertion tool of FIG. 6A.

FIGS. 7A-7C are perspective, bottom end, and side cross section views,respectively, showing a variation of the graft insertion tool preparedfor creating a second anastomosis of the bypass graft using thetwo-piece anastomosis staple device of FIG. 1.

FIGS. 8A-8G are side views of various configurations of the attachmentlegs of the anchor member of FIG. 1 which allow for tailored amounts oftissue compression at the anastomosis site.

FIG. 9 is a perspective view of a one-piece embodiment of theanastomosis staple device of the present invention.

FIG. 10 is a cross sectional view of the one-piece anastomosis stapledevice of FIG. 9 being actuated to form an end-to-side anastomosis.

FIG. 11 is a cross sectional view of a one-piece anastomosis stapledevice with extended first segments on the staple legs.

FIG. 12 is a cross sectional view of a one-piece anastomosis stapledevice with secondary pivot points on the staple legs to create radialtissue compression.

FIG. 13 is a side cross sectional view of a staple applying tool forcreating an end-to-side anastomosis using the one-piece anastomosisstaple device of FIG. 9.

FIG. 14 is a cross sectional view of the distal end of the stapleapplying tool of FIG. 13 holding the one-piece anastomosis staple deviceof FIG. 9 with a graft vessel attached thereto.

FIG. 15A is a detail drawing of the female bayonet connector on thedistal end of the anastomosis staple applying tool of FIG. 13. FIG. 15Bis an end view of the male bayonet connector on the proximal end of theone-piece anastomosis staple device of FIG. 9.

FIG. 16 is a cross sectional schematic of another alternate embodimentof the one-piece anastomosis staple device being actuated to form anend-to-side anastomosis.

FIGS. 17A-17B are a perspective views of a first alternate constructionof the two-piece anastomosis staple device of FIG. 1. FIG. 17C is across section view of the anchor member of the anastomosis staple deviceof FIG. 17A attached to the wall of a target vessel. FIG. 17D is a crosssection view of a completed anastomosis using the device of FIG.17A-17B.

FIGS. 18A-18F show a second alternate construction of the two-pieceanastomosis staple device of FIG. 1.

FIGS. 19A-19B shows a third alternate construction of the two-pieceanastomosis staple device of FIG. 1.

FIG. 20 is a side cross section view of a fourth alternate constructionof the two-piece anastomosis staple device of FIG. 1.

FIGS. 21A-21C are side partial cross section views of a first embodimentof an anastomotic fitting according to the invention.

FIGS. 22A-22C are side cross section views of an anastomosis fittingwhich is a variation of the embodiment of FIGS. 21A-21C. FIG. 22D is aproximal end view of the anastomosis fitting of FIG. 22C.

FIGS. 23A-23D are side cross section views of another variant of theembodiment of the anastomosis fitting of FIGS. 21A-21C and FIGS.22A-22C.

FIGS. 24A-24B are side cross section views of a second embodiment of theanastomotic fitting of the invention having an expanding inner flange.FIGS. 24C and 24D are distal end views of the expanding inner flange inthe collapsed position and the expanded position, respectively.

FIGS. 25A-25H show a second variant of the anastomotic fitting with anexpanding inner flange is shown in FIGS. 24A-24D.

FIGS. 26A-26I show a third embodiment which is a one-piece anastomoticfitting with a deformable outer flange.

FIGS. 27A-27D show a second variant of the anastomotic fitting with adeformable outer flange.

FIGS. 28A-28I show a third variant of the anastomotic fitting with adeformable outer flange.

FIGS. 29A-29C show an embodiment of the anastomotic fitting having asecondary flange washer which attaches to the inner flange.

FIGS. 30A-30K show an embodiment of the anastomotic fitting combiningdeformable inner staple members and an outer flange.

FIGS. 31A-31F show a first embodiment of an anastomotic device combininga fastening flange with a plurality of staple members.

FIGS. 32A-32F show an anastomosis device using preformed spring-likefastening staple members.

FIGS. 33A-33D show an anastomosis device using S-shaped staple membersthat pierce the interior wall of the target vessel.

FIGS. 34A-34D show an anastomosis device using S-shaped staple membersthat do not pierce the interior wall of the target vessel.

FIGS. 35A-35F show an anastomosis device using U-shaped staple memberswith barbed points.

FIGS. 36A-36C show an anastomosis device using U-shaped staple membersand a locking collar.

FIGS. 37A-37C show a second anastomosis device using U-shaped staplemembers and a locking collar.

FIGS. 38A-38C show a one-piece anastomosis device with integral staplemembers.

FIGS. 39A-39C show a second one-piece anastomosis device with integralstaple members.

FIGS. 40A-40D show a two-piece anastomosis device having two concentricring flanges with integral staple members.

FIGS. 41A-41E show an anastomosis device having a fastening flange and aplurality of individual staple members.

FIGS. 42A-42D illustrate a one-piece embodiment of the anastomosisdevice with a fastening flange and attached staple members.

FIGS. 43A-43B show the fastening flange of an anastomosis device usingpreformed superelastic alloy staple members in a top view and a sideview, respectively.

FIGS. 44A-44B show the superelastic alloy staple members of theanastomosis device in a front view and a side view, respectively.

FIGS. 45A-45E show the sequence of operations of an applicationinstrument for the anastomosis device of FIGS. 43A-43B and FIGS.44A-44B.

FIGS. 46A-46D illustrate a second embodiment of the anastomosis systemusing an anastomosis device with an inner fastening flange, an outerflange and staple members made of a superelastic alloy.

FIGS. 47A-47B show an anastomosis staple device combining a fasteningflange with precurved inner staple members of a highly resilientmaterial and deformable outer attachment legs in an undeployed state.

FIGS. 48A-48B show the anastomosis staple device of FIGS. 47A-47B in adeployed state.

FIGS. 49A-49C show the sequence of operations for deploying theanastomosis staple device of FIGS. 47A-47B.

FIGS. 50A-50B show a staple application instrument for applying theanastomosis staple devices of FIGS. 47A-47B.

FIG. 51 shows a combination strain relief and compliance mismatchtransition sleeve for use with any of the anastomosis devices of thepresent invention.

FIG. 52 shows a dual-balloon perfusion endoaortic clamp catheter forisolating a portion of the aortic wall while performing a proximalanastomosis in CABG surgery.

FIG. 53 shows a dual-balloon coronary isolation and perfusion catheterfor use in performing a distal anastomosis in CABG surgery.

FIG. 54 shows a T-shaped dual-balloon coronary isolation and perfusioncatheter for use in performing a distal anastomosis in CABG surgery.

FIGS. 55, 56, 57 show the sequence of operations for creating anend-to-side anastomosis during port-access CABG surgery using theanastomosis stapling system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be now be described in detail with reference to theaccompanying drawings. The detailed description describes the inventionin relation to a proximal anastomosis during CABG surgery for joiningthe proximal end of the bypass graft to the aortic wall. This example isgiven by way of illustration only and is in no way meant to be limiting.Those skilled in the art will recognize that the anastomosis stapledevice and anastomosis stapling system of the present invention arereadily adaptable for end-to-side connections of distal anastomoses(i.e. graft to coronary artery anastomoses) during CABG surgery, as wellas for use on other blood vessels and other tubular organs within thebody. For consistency and convenience, throughout the description thetwo ends of the anastomosis staple are referred to as the proximal anddistal ends of the staple, the distal end of the staple being the endwhich is closest to the inner lumen of the target vessel and theproximal end being the free end which is farthest from the inner lumenof the target vessel.

FIG. 1 is a perspective drawing of a first embodiment of the anastomosisstaple device of a first aspect of the present invention. Theanastomosis staple device 100 consists of two parts: an anchor member101, and a coupling member 102. The anchor member 101 forms theattachment to the exterior surface of the wall of a target vessel suchas the aorta. The coupling member 102 forms the attachment to the bypassgraft vessel. When the coupling member is joined to the anchor member,as shown by the dotted lines 103, it forms a complete anastomosis.

The anchor member 101 has a ring-shaped frame 104 which is configured toencircle an opening in the wall of a target vessel, such as the aorta.The ring-shaped frame 104 has a plurality of attachment legs 105,preferably six to twelve, circumferentially spaced around the frame 104and projecting from the distal end 106 of the ring. The anchor member101 is preferably made of stainless steel or a titanium alloy forstrength, biocompatibility and absence of MRI interference. Thering-shaped frame 104 and the attachment legs 105 preferably have a wallthickness of approximately 0.2 to 0.6 mm. The width of each of theattachment legs 105 is preferably between 0.5 and 2.0 mm. The attachmentlegs 105 could also be made with a round cross section to eliminatesharp edges which might propagate tears. The precise dimensions of theattachment legs 105 would be a compromise between making the legs rigidenough to pierce the wall of the target vessel without unduedeformation, yet flexible enough to permit the stapling mechanism todeform the attachment legs after they have pierced the target vesselwall to hold the anchor member in place. These dimensions may varydepending on which vessel is chosen as the target vessel for theanastomosis.

The attachment legs 105 extend first radially outward from the ring 104,then there is a transition curve 107, after which the legs 105 extendaxially away from the ring 104 in the distal direction. The transitioncurve 107 in each attachment leg 105 is shaped so that the anchor member101 can be placed precisely on the target vessel wall, then affixedfirmly in place with minimal displacement of the anchor member 101 ordistortion of the target vessel wall. This attachment process will bedescribed more fully in the operational description below.

The points of attachment between the attachment legs 105 and thering-shaped frame 104 in this illustrative embodiment are all shown asbeing coplanar with one another. In other preferred embodiments, thedistal extremity 106 of the anchor member 101 may be contoured to matchthe curvature of the exterior surface of the target vessel. Thus, thepoints of attachment between the attachment legs 105 and the ring shapedframe 104 will be arranged on a cylindrically curved surface whichintersects the ring 104 of the anchor member 101 rather than a plane.This would be especially important when there is closer parity betweenthe diameter of the graft vessel and the diameter of the target vessel,such as when performing a distal anastomosis between a venous orarterial graft and a coronary artery, because a planar arrangement ofthe attachment legs 105 would not approximate the curvature of thetarget vessel wall as well as for a larger target vessel such as theaorta. In other alternate embodiments, the distal end of the anchormember 106 and the attachment legs 105 may be angled with respect to thering-shaped frame 104 to permit an angled takeoff of the graft vesselfrom the target vessel.

One preferred configuration for the transition curve 107 in theattachment legs 105 is illustrated in FIG. 1. The first segment 108 ofeach attachment leg extends radially from the ring-shaped frame for ashort distance. The second segment 109 of each leg angles proximallyfrom the first segment at approximately 60° for a short distance. Then,the third segment 110 angles approximately 60° in the distal directionfrom the second segment 109. The fourth segment 111 extends in thedistal direction from the third segment 110 so that the fourth segment111 extends axially away from the ring-shaped frame 104 parallel to thecentral axis of the ring 104. The second 109 and the third 110 segmentsshould be approximately equal in length to one another. The actuallength of the second 109 and third 110 segments will be determined bythe wall thickness of the target vessel. A typical length of 1.5-5 mmwould be used for attachment to the wall of the aorta. The distal ends112 of the attachment legs 105 are sharpened to easily penetrate theaortic wall.

This illustrates just one preferred transition curve 107 for theattachment legs 105. Alternate transition curves 107 for the attachmentlegs 105 may include arc-shaped segments in place of some of thestraight segments or may include a greater number of straight segmentsto approximate a smoother curve. When choosing alternate curves, it isimportant to preserve the axially extending final segment 111 of theattachment legs in order to penetrate the target vessel wall. Inaddition, it is important to control the amount of distortion of thetarget vessel wall when the anchor member 101 is attached. This is incontrast to many standard wound closure staples which deliberately bunchup the tissue when they are applied to create a closer approximation ofthe tissues being joined. This type of distortion may becounterproductive in attaching a graft vessel to the aortic wall becausethe wall may be too stiff to distort in this manner and the distortionmight cause problems in creating a leak proof seal at the anastomosis.The anvil geometry of the stapling mechanism will also be important indetermining the optimum geometry of the attachment legs.

The amount of radial compression of the target vessel wall around theanastomosis can be tailored by the choice of the transition curve 107 inthe attachment legs 105 of the anchor member 101. Radial compression ofthe target vessel wall around the anastomosis helps to create andmaintain an anastomotic seal between the target vessel and the graftvessel in the completed anastomosis. This is especially important whenblood pressure is restored in the target vessel which will tend tostretch the target vessel wall and pull it away from the anastomosis.The radial compression by the attachment legs counteracts this expansionand maintains the anastomotic seal under pressure. FIGS. 8A-8G showvarious other possible geometries for the attachment legs 105 of theanchor member 101 arranged according to the degree of tissue compressionapplied to the target vessel wall. FIG. 8A shows a staple attachment leg105 where the transition curve 107 consists of a straight second segmentwhich extends upward at ninety degrees from the first radially extendingsegment. The third segment 110 describes a 90° arc with a center ofrotation at the transition point between the first 108 and second 109segments. The fourth segment 111 extends straight in an axial directionfrom the third segment 110. This embodiment of the attachment legs 105creates very little tissue compression when applied. The amount oftissue compression is indicated by the shaded region between thestraight insertion path of the fourth segment 111 and the final positionof the actuated staple shown in phantom lines 105. FIG. 8B shows atransition curve 107 with an elliptically shaped second segment 109which smoothly evolves into an arc-shaped third segment 110 with acenter of rotation at the transition point between the first 108 andsecond 109 segments. This embodiment creates a slightly greater degreeof tissue compression. FIG. 8C shows an attachment leg geometry which isformed entirely of smooth curves so as to avoid any sharp bends in theattachment legs 105, but which produces approximately the same tissuecompression as the attachment leg of FIG. 8B. FIG. 8D shows a transitioncurve 107 with a 30° arc-shaped second segment 109 connecting to a 30°arc-shaped third segment 110 with a center of rotation at the transitionpoint between the first 108 and second 109 segments. FIG. 8E shows aside view of the embodiment illustrated and described above in FIG. 1.The second segment 109 angles 60° upward from the first segment 108, andthe third segment 110 angles downward at 60° from the second segment109. This produces a selected degree of tissue compression when theattachment legs 105 are actuated. FIG. 8F shows an attachment leggeometry which produces slightly greater tissue compression in thetarget vessel. The second 109 and third 110 segments of the transition107 are smoothly blended together in a continuous semicircular arc. FIG.8G shows an attachment leg geometry which produces even more tissuecompression. The second segment 109 angles upward at 45° from the firstsegment 108 and the third segment 110 angles downward from the second109 at a 90° angle. Many other attachment leg geometries may be tailoredto produce the desired degree of tissue compression in the targetvessel.

The coupling member 102, as seen in FIG. 1, has a tubular body 113 witha passage 114 through it. The distal end of the coupling 102 has anatraumatic edge 115 over which the graft vessel will be everted informing the anastomosis. The atraumatic edge 115 is important to avoidpiercing or damaging the vessel wall in the vicinity of the anastomosiswhich occurs with some prior art devices. Atraumatic attachment of thegraft vessel to the coupling member helps to assure a reliableanastomotic seal between the graft vessel and the target vessel andreduces the likelihood of mechanical failure of the graft vessel walldue to punctures or tears in the wall. The exterior of the couplingmember 102 is sized to fit into the interior of the ring-shaped frame104 of the anchor member with enough space between them to accommodateone wall thickness of the bypass graft. The coupling member 102 ispreferably made of stainless steel, a titanium alloy or plastic with awall thickness of approximately 0.1 to 0.6 mm. The exterior of thecoupling member 102 has exterior surface features 116 which serve a dualpurpose. The exterior surface features 116 serve to hold the everted endof the bypass graft onto the coupling member 102, as well as tointerlock the coupling member 102 with the anchor member 101 to completethe anastomosis. Likewise, the interior of the anchor member 101 is madewith interior surface features 117 which interact with the exteriorsurface features 116 to create the interlock. The exterior surfacefeatures 116 of the coupling member 102 could be in the form of bumps,pins, points, barbs, ridges, threads, holes or a combination of thesefeatures. The interior surface features 117 of the anchor member 101would then be in the form of corresponding bumps, pins, points, barbs,ridges, threads or holes to lock the two parts together. It should benoted that, if pins, points, barbs or other piercing members are used asthe interior 117 or exterior 116 surface features of the anastomosisstaple device 100, these potentially traumatic features are located awayfrom the everted edge of the graft vessel and outside of the lumens ofthe graft vessel and target vessel that will serve as the conduit of thebypass so as not to compromise the integrity of the anastomosis.

In the embodiment illustrated, the coupling member 102 is shown withbump-shaped exterior surface features 117 that hold the everted graftvessel onto the coupling member 102 and interlock with a series ofcircumferential ridges 116 within the anchor member 101. The interiorridges 116 of the anchor member 101 permit a variable degree ofengagement between the coupling member 102 and the anchor member 101 toallow for different wall thicknesses of the target vessel and the graftvessel used in the anastomosis. The axial position of the couplingmember 102 with respect to the anchor member 101 can be varied to createthe desired degree of axial tissue compression to assure an anastomoticseal despite variations in the vessel wall thicknesses.

The complete anastomosis stapling system includes the anastomosis stapledevice 100 and an instrument 118 for applying the anastomosis staple100. The instrument 118 for applying the two-part anastomosis staple 100consists of three separate, but interacting, mechanisms: a staplingmechanism 119, a vessel punch mechanism 120, and a graft insertion tool121, 122. Together with the anchor member 101 and the coupling member102, they comprise a complete system for performing an anastomosis. InFIG. 2, we can see two of these mechanisms, the stapling mechanism 119and the vessel punch mechanism 120, assembled together with the anchormember 101 of the anastomosis staple 100, prepared for the first stageof the anastomosis procedure. The third mechanism, the graft insertiontool, is shown in two different embodiments 121, 122 in FIGS. 6A-6C andFIGS. 7A-7C, respectively.

The stapling mechanism 119 and the vessel punch 120 are shown assembledtogether in a perspective view in FIG. 2. The anchor member 101 of theanastomosis staple 100 is held by the staple retainer 123 on the distalend of the stapling mechanism. This same assembly can be seen in crosssection in the operational drawings 5A-5C. The distal end of thisassembly is shown in greater detail in cross section in FIG. 4. Thestapling mechanism 119 has an inner tube 124 and an outer tube 125 whichare threaded together at their distal ends. The outer tube 125 has ahandle 126 at the proximal end and an annular staple driver 127 at thedistal end of the tube. The inner tube 124 has a staple retainer 123 forholding the anchor member 101 of the anastomosis staple 100 on thedistal end of the tube. The inner tube 124 has an internal lumen 128 ofsufficient size to accommodate the vessel punch mechanism 120 and thegraft insertion tool 121, alternately. The proximal end of the innertube 124 has a pair of opposing slots 129 on the inner surface that actas splines for engagement with a corresponding pair of lugs 130, 134 onthe exterior of the vessel punch mechanism 120 and on the graftinsertion tool 121.

The vessel punch mechanism 120 is sized to fit through the internallumen 128 of the inner tube 124 of the stapling mechanism 119. Thevessel punch mechanism 120 has an outer tube 131 and an inner drivemember 132 slidably received within the outer tube. The proximal end ofthe outer tube 131 is attached to a T-shaped handle 133. The outer tube131 has a pair of lugs 130 near the proximal end which extend radiallyfrom the exterior of the tube 131 to engage the opposing slots 129 inthe inner tube 124 of the stapling mechanism 119. The distal end of theouter tube 131 tapers to form a neck 135 which attaches to a cutteranvil 136. The vessel punch cutter 137 is a tubular member which slidestelescopically on the distal end of the outer tube 131 of the vesselpunch 120. The distal edge 138 of the tubular cutter 137 is sharpenedwith an approximately conical bevel 138. The outer tube 131 of thevessel punch mechanism 120 may include a step 139 against which thecutter is located in the retracted position as in FIGS. 5A and 5B. Thetubular cutter 137 is attached to the drive member by a transverse pin140 which extends through a pair of opposing slots 141 in the distal endof the outer tube 131. The proximal end of the drive member 132 isattached to an actuating plunger 142 which extends proximally of theT-shaped handle 133.

The vessel punch mechanism 120 is actuated by pressing on the actuatingplunger 142 to move it with respect to the T-shaped handle 133. Thislinear motion is transferred to the inner drive member 132 and then, inturn, to the tubular cutter 137 by way of the transverse pin 140. Thetubular cutter 137 slides forward until the inner lumen of the cutter137 slides over the anvil 136 in a shearing action. There is a verytight clearance between the inner lumen of the cutter 137 and the outerdiameter of the anvil 136. This tight clearance assures a cleanly cuthole through the vessel wall without ragged or torn edges. In FIG. 5C,the vessel punch mechanism 120 is shown actuated to cut a hole throughthe aortic wall tissue.

FIG. 3 is a large scale perspective detail drawing of the distal end ofthe vessel punch mechanism 120 assembled with the stapling mechanism119. The anchor member 101 of the anastomosis staple 100 is held by thestaple retainer 123 on the distal end of the inner tube 124 of thestapling mechanism 119. The ring-shaped frame 104 of the anchor member101 fits inside of a counterbore 143 on the distal end of the innertube, as can be seen in FIGS. 4 and 5A-5E. The attachment legs 105 ofthe anchor member 101 are captured and held by the L-shaped grippingfingers 144 which extend from the distal end of the inner tube 124.There are an equal number of gripping fingers 144 on the inner tube 124as there are attachment legs 105 on the anchor member 101. Each grippingfinger 144 has an axial slot 145 alongside of it which is at least aswide as the attachment legs 105. The axial slot 145 connects with atransverse slot 146 in the side of each gripping finger 144. The anchormember 101 of the anastomosis staple 100 is loaded onto the stapleretainer 123 by aligning the attachment legs 105 with the ends of theaxial slots 145, pushing the attachment lees 105 to the bottom of theaxial slots 145, then turning the anchor member 101 counterclockwiseuntil the attachment legs 105 enter the transverse slots 146 in the sideof the gripping fingers 144. The anchor member 101 can be secured inthis position by rotating the outer tube 124 of the stapling mechanismto advance it distally until the staple driver 127 contacts theattachment legs 105 with enough force to hold the anchor member 101 inplace without deforming the legs. Alternatively, the inner tube 124 ofthe stapling mechanism 119 could be adapted to grip the ring-shapedelement 104 of the anchor member 101 directly.

The T-shaped handle 133 of the vessel punch mechanism 120 also serves asthe handle for the inner tube 124 of the stapling mechanism 119 at thisstage of the procedure because the lugs 130 on the exterior of thevessel punch outer tube 131 engage the slots 129 in the interior of thestapler inner tube 124. Likewise, in the latter stages of the procedure,the T-shaped handle 133 of the graft insertion tool 121 can also serveas a handle for the inner tube 124 of the stapling mechanism 119 becausethe lugs 134 of the graft insertion tool 121 engage the inner slots 129of the stapler inner tube 124 in a similar fashion. Alternatively, theinner tube 124 of the stapling mechanism may be supplied with a separatehandle or knob of its own so the inner 124 and outer 125 tubes of thestapling mechanism can be rotated with respect to one another to operatethe stapling mechanism when neither the aortic punch mechanism 120 northe graft insertion tool 121 is inserted into the stapling mechanism119.

A first embodiment of the graft insertion tool 121 and its relationshipto the coupling member 102 of the anastomosis staple 100 are shown indetail in FIGS. 6A-6C. This embodiment of the graft insertion tool 121may be used when the anastomosis staple 100 is used to form the firstanastomosis of the bypass procedure no matter whether the firstanastomosis is the proximal or the distal anastomosis of the graft. Toprepare the bypass graft for creating the anastomosis, the couplingmember 102 is first loaded onto the distal end of the graft insertiontool 121. A shoulder 147 on the graft insertion tool 121 holds thecoupling member 102 in the correct position, and a tight interferencefit or a spring action prevents it from inadvertently falling off. Thegraft vessel 148 is then loaded into the internal lumen 149 of the graftinsertion tool 121. This can be done by tying a suture around the graftvessel on the end opposite to the end that will be anastomosed, passingthe suture through the internal lumen 149 of the graft insertion tool121, then drawing the graft vessel 148 into the lumen until the end 192of the graft vessel 148 to be anastomosed extends a short distance fromthe distal end of the graft insertion tool 121. Alternatively, a specialtool, such as a narrow pair of endoscopic forceps or a nerve hook, maybe used for grasping the graft vessel 148 and drawing it through thegraft insertion tool 121. At this point, the end 192 of the graft vessel148 to be anastomosed is everted over the end of the graft insertiontool 121 and the coupling member 102, as shown in FIGS. 6A-6C. Theexternal surface features 116 of the coupling member 102 serve to holdthe graft vessel onto the exterior of the coupling member 102 in theeverted position. The external surface features 116 of the couplingmember may at least partially penetrate the wall of the graft vessel 148to provide greater holding force.

With the anchor member 101 loaded onto the stapling mechanism 119 andthe graft vessel 148 prepared by everting and attaching it to thecoupling member 102 as described above, the device is ready to performthe end-to-side anastomosis, as illustrated in FIGS. 5A-5G. Referringnow to FIG. 5A, the stapling mechanism 119 and the vessel punchmechanism 120 are shown assembled together. A slit 150 is made in thetarget vessel wall 150 with a scalpel or other sharp instrument, and theanvil 136 of the vessel punch 120 is inserted through the slit 151 intothe lumen of the target vessel 150. The anvil 136 serves to center thestapling mechanism 119 and the anchor member 101 around the chosenattachment point on the target vessel 150 where the slit 151 is made.The stapling mechanism 119 is advanced over the vessel punch mechanism120 toward the wall of the target vessel 150, as shown in FIG. 5B. Aslight tension is maintained on the T-handle 133 of the vessel punchmechanism 120 so that the anvil 136 supports the wall of the targetvessel 150 as the attachment legs 105 of the anchor member 101 contactand penetrate the target vessel wall 150. The fourth segments 111 of theattachment legs 105 penetrate the target vessel wall 150 in a linearpath. Once the fourth segments 111 of the attachment legs 105 havetraversed the target vessel wall 150, the attachment legs 105 areactuated, as shown in FIG. 5C. The outer tube 125 of the staplingmechanism 119 is advanced over the inner tube 124 by rotating the handle126 of the outer tube 125 with respect to the T-handle 133 of the vesselpunch mechanism 120. This advances the staple driver 127 against theattachment legs 105, deforming them into the position shown in FIG. 5C.After the attachment legs 105 have been actuated, the tubular cutter 137of the vessel punch mechanism 120 is advanced with respect to the anvil136, as shown in FIG. 5D, by pressing on the actuating plunger 142 atthe proximal end of the drive member 132. The punch mechanism 120creates an opening 152 through the target vessel wall 150. The vesselpunch mechanism 120 with the tissue 153 that was excised by the punchcan now be withdrawn from the inner lumen 128 of the stapling mechanism119, as shown in FIG. 5E, leaving the anchor member 101 attached to thetarget vessel wall 150 in alignment with the opening 152 punchedtherein.

The graft vessel insertion tool 121 with the prepared graft vessel 148and coupling member 102 in place is inserted into the inner lumen 128 ofthe stapling mechanism 119 as shown in FIG. 5F. The coupling member 102is pressed into the ring-shaped frame 104 of the anchor member 101 andthe exterior features 116 on the coupling member 102 engage the interiorfeatures 117 of the ring-shaped frame 104 to hold the coupling member102 and the anchor member 101 together. The staple retainer 123 of thestapling mechanism 119 still has a firm grasp on the anchor member 101to provide support as the coupling member 102 is pressed into thering-shaped frame 101. The coupling member 102 should be pressed intothe ring-shaped frame 104 until the everted end of the graft vessel 148bears against the exterior surface of the target vessel wall 150,creating a fluid tight seal at the anastomosis site. Alternatively, thecoupling member 102, with the everted end of the graft vessel 148attached. can be made to extend into the opening 152 in the targetvessel wall 150 with the target vessel wall 150 creating a radialcompression around the graft vessel 148 and the coupling member 102. Thestapling mechanism 119 can now be disengaged from the from the anchormember 101 by turning the handle 126 of the outer tube 125 with respectto the T-handle 133 of the graft insertion tool 121 until the stapledriver is withdrawn from the attachment legs 105. Then the inner tube124 of the stapling device can be turned counterclockwise by turning theT-shaped handle 133 of the graft insertion tool 121 to disengage thegripping fingers 144 of the staple retainer 123 from the attachment legs105 of the anchor member 101. A complete end-to-side anastomosis, asshown in FIG. 5G, is left at the anastomosis site.

It should be noted that the order of the steps of the anastomosisprocedure 127 could be altered. For instance, the opening could be firstpunched in the target vessel with an aortic punch or similar instrument,and then the anchor member of the staple could be attached. In thisinstance, the graft vessel could be attached to the anchor member eitherbefore or after the anchor member is attached to the target vessel.Other variations in the order of the steps are also possible.

FIG. 7A shows a perspective drawing of a second embodiment of the graftinsertion tool 122 for use in performing the second anastomosis on agraft vessel, one end of which has already been anastomosed, or forother situations when both ends of the graft vessel are not available,such as when making the distal anastomosis on an internal mammary arterybypass graft. This embodiment of the graft insertion tool 122 is madewith a two-part, hinged holder 154 for the coupling member of theanastomosis staple device so that the holder 154 can be removed fromaround the graft vessel 148 after both ends of the graft have beenanastomosed. The holder 154 is attached to the distal end of a tubularmember 155 which is attached on its proximal end to a handle grip 156. Ashaft 157 is slidably received within the tubular member 156. The distalend of the shaft 157 is attached to a U-shaped yoke 158 which isconfigured to grip a flange 159 or a pair of lugs on the proximal end ofthe anchor member 101. The handle grip 156 has a coacting trigger member160 which is attached to the proximal end of the shaft 157 through aslot 161 in the side of the tubular member 155. The holder 154 is springbiased toward the open position 154′. The force of the spring actionhelps the holder 154 to grip the coupling member 102 so that it does notslip off of the holder 154 prematurely. A distal end view of the holder154 is shown in FIG. 7B, with the holder 154 shown in both the closedposition and the open position (phantom lines 154′).

To prepare the graft vessel 148 for the anastomosis, the coupling member102 is first placed onto the holder 154 and the end of the graft vessel148 to be anastomosed is passed through the lumen 162 of the holder 154and the coupling member 102 from the proximal to the distal end. The endof the graft vessel 148 is then everted back over the coupling member102, as shown in FIG. 7C. The external surface features 116 on thecoupling member 102 will hold the everted vessel in place on thecoupling member. In FIG. 7C, the anchor member 101 of the anastomosisstaple device 100 has been fastened to the target vessel 150, asdescribed above in relation to FIGS. 5A-5E, and the stapling mechanism119 has been removed by turning the handle 126 of the stapling mechanism119 counterclockwise relative to the handle 126 on the vessel punchmechanism 120 until the anchor member 101 is released. The graftinsertion tool 122 with the prepared graft vessel 148 is now positionedat the anastomosis site and the U-shaped yoke 158 is used to grip theanchor member 101, retained by the flange 159 on its proximal end. Withthe graft vessel 148 and the coupling member 102 aligned with the anchormember 101 as shown, the handle grip 156 and the trigger 160 aresqueezed together to press the coupling member 102 into the anchormember 101 until the everted end of the graft vessel 148 is pressedagainst the outer surface of the target vessel 150 creating a leak-proofanastomosis. The holder 154 is then retracted from the coupling member102 by moving the trigger 160 away from the handle grip 154. The hingedholder 154 opens when it is withdrawn from the coupling member 102,releasing the graft vessel 148 from the lumen 162 of the holder 154. TheU-shaped yoke 158 can now be slid sideways off of the anchor member andthe anastomosis is complete.

A one-piece version of the anastomosis staple device of the presentinvention along with a specially adapted staple applying tool will nowbe described in detail. In the one-piece embodiments which follow, atubular member, analogous to the coupling member of the previouslydescribed embodiment, is permanently attached to a circular staplemember, which is analogous to the anchor member 101 of the previouslydescribed embodiment.

FIG. 9 shows a perspective view of a first embodiment of the one-pieceanastomosis staple device 163 of the present invention. This sameembodiment is shown in cross section in FIGS. 11 and 13. The anastomosisstaple 163 has a tubular body member 164 which has an inner lumen 165sized to accommodate the exterior diameter of the graft vessel 148.Means for attaching the graft vessel 148 are provided at the distal endof the tubular body member 164 or on the outside of the tubular member164. In the preferred embodiment, the means for attaching the graftvessel 148 to the anastomosis staple 163 is a tubular distal extension166 of the tubular body over which the graft vessel 148 is everted. Thetubular extension 166 may include a flange 167 to secure the attachmentof the everted graft vessel 148 to the tubular extension 166. Thisflange 167 may also engage the inner surface of the target vessel 150 tohelp retain the graft 148 in place.

The anastomosis staple device 163 has a multiplicity of staple legs 168extending from the tubular body member 164 proximal to the tubulardistal extension 166. Optionally, the tubular body member 164 may extendproximally 169 from the staple legs 168 as shown, or the tubular bodymember can be truncated at or near the level of the staple legs todecrease the overall profile of the staple. The optional proximalextension 169 of the tubular body member 164 may include lugs or tabs170 or a flange or other features that can be used for gripping thestaple 163 by a staple applying tool.

The anastomosis staple 163 typically has five to twelve staple legs 168for attaching to the target vessel wall 150. The presently preferredembodiment of the staple 163 has six staple legs 168 as illustrated inFIG. 9. The staple leas 168 are distributed circumferentially around theexterior of the tubular body member 164. The staple legs 168 can beformed integrally with the tubular body member 164, or they can bemanufactured separately and attached to the tubular body member 164.Optionally, the exterior of the tubular body member 164 may include acircumferential ledge 171 to which the staple legs 168 are attached. Inthe pre-actuated position, the legs 168 angle proximally from where theyattach to the tubular body member 164 so that the sharpened tips 172 ofthe staple legs are proximal to the point of attachment with the body.The staple legs 168 have a first segment 173 which extends approximatelystraight from the tubular body member: then there is a transitionalsegment 174 and a curved end segment 175. The curved end segment 175 ofeach staple leg has a sharpened tip 172 for easily piercing the wall ofthe target vessel 150. The curve of the end segment 175 is a circulararc whose center of rotation coincides approximately with the point ofattachment 176 between the staple leg and the tubular body member. Thepoint of attachment 176 serves as a pivot point for the staple leg 168when it is actuated, so that the end segment 175 of the staple legs 168describes an arc-shaped path through the tissue of the target vesselwall that follows the curvature of the arc-shaped end segment 175.

The transition segment 174 of the staple legs 168 can take on one ofseveral forms depending on the effect desired in the actuated staple. Ifthe transition segment 174 is largely a right-angle bend, so that onlythe end segment 175 penetrates the tissue, then the staple legs 168 willcause very little radial compression of the target vessel wall tissue150 as the staple 163 is actuated. If, on the other hand, the transitionsegment 174 has a curve of smaller radius than that of the curved endsegment 175, the tissue will be compressed and pulled toward the tubularbody member 164 as the transition segment 174 enters and travels throughthe target vessel wall 150, as illustrated in FIG. 10. The degree ofradial tissue compression can be regulated to the appropriate amount byproper design of the curve in the transition segment 174 of the staplelegs 168. In addition, the shape of the first segment 173 may help todefine the surface shape of the target vessel 150 after the staple 163is applied. It may be desirable to keep it as flat as possible, or itmay be desirable to “tent up” the target vessel somewhat in the area ofthe anastomosis. Optionally, the first segment may be given greatereffect on the target vessel surface shape by extending the first segment173 beyond the transition point with the second segment 174, as shown inFIG. 11. The straight extension 177 of the first segment 173 beyond theattachment point of the transition curve 174 will tend to flatten outthe tissue of the target vessel wall 150 at the anastomosis site so thatundue deformation of the vessel wall does not compromise the integrityof the anastomosis.

FIG. 12 shows another means for accomplishing the tissue compressionperformed by the transition segment 174 of the staple legs 168 in theembodiment of FIGS. 9 and 10. In this embodiment, the transition segment174 of the staple legs 168 is essentially a right angle bend with verylittle radiusing, so the staple legs 168 cause very little tissuecompression as they pierce the target vessel wall 150 and travel throughthe tissue. However, before the staple legs 168 have reached the end oftheir travel, the first segment 173 comes into contact with acircumferential ledge 178 that extends outward from the tubular bodymember 164 just below the attachment point 176 of the staple legs 168.When the staple legs 168 contact the ledge 178, the first segments 173of the legs bend where they contact the outer edge of the ledge 178.This moves the center of rotation outward and shortens the radius ofrotation of the curved end segment 175 so that the staple legs will pullthe tissue of the target vessel wall 150 toward the tubular body member164, compressing the tissue.

The staple legs 168 are preferably dimensioned so that the staple legstravel all the way through the target vessel wall 150 when the staple isactuated. In the embodiment of FIG. 10, after actuation, the ends 172 ofthe staple legs 168 rest just distal to the flange 167 on the distal end166 of the tubular body member 164. In the embodiment of FIG. 12, thestaple legs 168 are configured to pierce the wall of the graft vessel148 just proximal to the flange 167 on the distal end 166 of the tubularbody member 164, adding to the security of the attachment. In bothembodiments the flange 167 supports the tissue of the target vessel wall150 as the ends 172 of the staple legs 168 emerge, helping to insurethat the staple legs 168 will pierce cleanly through the target vesselwall 150 without separating the lamina, which could lead to dissection.In both cases, the staple legs 168 are configured so that the curved endsegments 175 of the staple legs 168 are driven all the way through thetarget vessel wall 150 before there is significant compression of thetissues. The tubular body member 164 isolates the cut edge at theopening 152 in the target vessel wall 150 from the blood flow path sothat blood pressure will not cause delamination of the target vesselwall 150. The staple legs 168, the tubular body member 164 and theflange 167 form a closed loop, similar to a sutured attachment. Thesefactors also help to minimize the danger of dissection of the targetvessel wall 150.

FIG. 13 shows one preferred embodiment of the one-piece anastomosisstaple 163 mounted on the distal end of a specially adapted stapleapplying tool 179. The staple applying tool 179 has an outer tube 180and an inner tube 181 slidably received within the outer tube 180. Theinner tube 181 has an inner lumen 182 of sufficient diameter toaccommodate the outer diameter of the graft vessel 148 that will be usedfor the anastomosis. The staple applying tool 179 has a main body 183which is shaped in the form of a pistol grip. The proximal end of theinner tube 181 is anchored with respect to the main body 183 by a flange184 or other attachment on the proximal end. The outer tube 180 isslidable with respect to the inner tube 181 by actuating the lever 185of the staple applying tool 179 which engages a pair of pins 186attached to the exterior of the outer tube. Pulling the lever 185advances the outer tube 180 distally over the inner tube 181. A returnspring 187 attached to the lever 185 returns the lever 185 and the outertube 180 to their unactuated positions.

A close-up view of the anastomosis staple 163 and the distal end of thestaple applying tool 178 is shown in FIG. 14. The anastomosis staple 163in this embodiment has a tubular body 164 which is permanently attachedto a plurality of circumferentially distributed attachment legs 168. Thetubular body 164 has a distal tubular extension 166 with a flange 167for eversion and attachment of the graft vessel 148. There is also aproximal tubular extension 169 which has a pair of tabs 170 for graspingthe staple with a staple retainer 188 on the distal end of the innertube 181 of the staple applying tool 179. An end view of the tabs 170 isshown in FIG. 15. The staple retainer 188 at the distal end of the innertube 181 shown in detail in FIG. 15B, has a pair of longitudinal slots189 corresponding to the two tabs 170 of the anastomosis staple.Connected to the longitudinal slots 189 is a circumferential groove 190within the inner tube 188. The staple 163 is attached to the stapleretainer 188 by aligning the tabs 170 with the longitudinal slots 189and sliding the tabs into the slots 189. When the tabs 170 reach thebottom of the longitudinal slots 189, the staple 163 is rotated withrespect to the inner tube 181 so that the tabs 170 enter thecircumferential groove 190. A ridge 191 on the distal side of the groove190 holds the tabs 170 within groove 190 to retain the staple 163 on theend of the inner tube 181.

It should be noted that a number of methods of attaching the tubularmember 164 to the stapling mechanism 179 are possible besides thebayonet attachment illustrated. The end of the stapling mechanism 179may be configured to grasp the tubular member 164 on the inner diameteror the outer diameter distal to the point of attachment 176 of thestaple legs 168, allowing the proximal tubular extension 169 of theanastomosis staple 163 to be eliminated. This modification would allow alower profile anastomosis attachment to be created.

To prepare the graft vessel 148 for anastomosis, an anastomosis staple163 is attached to the distal end of the staple applying tool 179 asjust described, then, using a suture or an elongated grasping tool, thegraft vessel 148 is drawn into the inner lumen 182 of the tool until theend 192 of the graft vessel 148 to be anastomosed extends a shortdistance from the distal end of the tool. At this point, the end 192 ofthe graft vessel 148 to be anastomosed is everted over the distaltubular extension 166 and the flange 167 as shown in FIG. 14. A suturecan be tied around the everted end 192 of the graft vessel 148 proximalto the flange 167 to retain the graft vessel 148 on the staple 163, ifdesired.

Thus prepared, the staple 163 is advanced toward an opening 152 that hasbeen previously made in the target vessel wall 150 with an aortic punchor other appropriate tool. Preferably, the opening 152 is made with adiameter approximately equal to the outer diameter of the distal tubularextension 166 of the staple 163 just proximal to the flange 167. Theflange 167 with the everted end 192 of the graft vessel 148 is passedthrough the opening 152 in the target vessel 150, as shown in FIG. 10.The target vessel wall 150 may need to be stretched slightly to allowthe flange 167 to pass through the opening 152. The elastic recovery ofthe target vessel wall 150 creates a compressive force where the targetvessel wall 150 surrounds the distal tubular extension 166 with theeverted end 192 of the graft vessel 148 which contributes to thefluid-tight seal of the anastomosis.

Once the flange 167 has been passed through the opening 152 in the wallof the target vessel 150, the anastomosis staple 163 is pulled backslightly so that the flange 167, covered by the everted graft vesselwall 192, is against the inner surface of the target vessel wall 150.Then, the staple 167 is actuated by pulling on the lever 185, whichmoves the outer tube 180 distally until the staple driver 193 at thedistal end of the outer tube 180 bears on the attachment legs 168. Asthe staple driver 193 advances, the attachment legs 168 bend at thefulcrum 176 where they attach to the tubular member 164. The arc-shapedthird segments 175 of the attachment legs 168 penetrate and traverse thewall of the target vessel 150. Once the third segments 175 of theattachment legs 168 have traversed the wall, the staple 163 begins tocompress the tissue of the target vessel wall 150 radially against thedistal tubular extension 166 of the anastomosis staple 163 by any of themechanisms previously discussed. After the attachment legs 168 of theanastomosis staple 163 have been fully actuated, the lever 185 isreleased and the staple applying tool 179 is rotated to disengage thestaple retainer 188 from the tabs 170 on the proximal tubular extension169 of the staple 163. The staple applying tool 179 is withdrawn and theanastomosis is complete.

FIG. 16 shows another potential configuration for the staple legs 194 ofthe one-piece anastomosis staple 195. In this embodiment, the staplelegs 194 have a compound curved transition segment 197 which providestwo different axes of rotation for the staple legs 194 as they areactuated. The staple legs 194 attach to the proximal end of the tubularbody member 198. A first segment 199 of the staple leg 194 extendsapproximately radially from the point of attachment 206. There is aU-shaped bend 200 at the end of the first segment 199 that connects itto a second segment 201 which lies roughly parallel to the first segment199. A third segment 202 attaches the second segment 201 to the fourth,and most distal, segment 203 of the staple leg. The fourth segment 203has an arc-shaped curve whose center of rotation is approximately at thecenter of the U-shaped curve 200 between the first 199 and second 201segments. The distal tip 204 of the fourth segment 203 is sharpened sothat it easily penetrates the target vessel wall 150.

In the operation of this embodiment of the anastomosis staple, thestaple legs 194 are initially in the position shown by solid lines 194in FIG. 16. In this position the staple legs 194 are held well above theflange 205 on the distal end of the tubular body member, making iteasier to insert the flange 205, with the everted graft vessel 192attached, into the opening in the target vessel 150 and to seat theflange 205 against the inner surface of the target vessel 150. When thestaple driver is advanced, the staple legs 194 initially rotate aboutattachment point 206 between the first segment and the tubular bodymember. After the staple leg 194 has rotated approximately, 90 degrees,to the position shown by phantom lines 194′, the first segment 199 comesinto contact with the exterior of the tubular body member 198 and itstops rotating. Advancing the staple driver further causes the second201, third 202 and fourth 203 segments of the staple leg 194 to rotatearound the U-shaped curve 200 connecting the first 199 and second 201segments. The U-shaped curve 200 opens up to about 90 degrees as thecurved fourth segment 203 of the staple leg 194″ penetrates the targetvessel wall 150, attaching the graft vessel 148 to the target vessel 150to complete the anastomosis.

Another embodiment of the two-piece anastomosis staple is shown in FIGS.17A-17D. This embodiment differs somewhat in its construction from theembodiment of FIG. 1 although the operational principles are basicallythe same. The anastomosis staple 207 again includes an anchor member 208and a coupling member 209 which interconnect. The anchor member 208 ismade with a ring-shaped frame 210 which is pierced by two parallel rowsof slots 211, 212. The metal 213 between the slots 211, 212 is deformedoutward slightly to allow insertion of wire attachment legs 214. Afterthe attachment legs 214 are inserted, the metal 213 is pressed inward tofirmly attach the wire attachment legs 214 to the frame 210. Eitherbefore or after attachment to the ring-shaped frame 210, the wireattachment legs 214 can be formed with a desired curve, such as one ofthe curves described in FIGS. 8A-8G. The distal tips 215 of the wireattachment legs are sharpened so that they easily penetrate the targetvessel wall 150. The use of round wire attachment legs 214 withconically sharpened points 215, as opposed to the flat attachment legs105 with chisel-shaped points 212 of FIG. 1, has shown some advantage inpreliminary testing, in that the round wire legs 214 cause less traumato the tissue of the target vessel wall 150 as they penetrate it. Thismay be due to the tendency of the conically sharpened tips 215 of theattachment legs 214 to dilate the tissue as they pass through the targetvessel wall 150 more than to cut it. The tissue of the target vesselwall 150 is thus left more intact and may be less prone to dissectionsor other structural failure.

A plurality of retaining clips 216 are integrally formed on the proximaledge of the ring-shaped frame 210. The retaining clips 216 perform thefunction of coupling the anchor member to the coupling member, similarto the interior surface features 117 of the anchor member 101 of FIG. 1.The coupling member 209, shown in FIG. 17B, has a tubular body 217 witha plurality of graft holding points 218 extending from its distal edge.If desired, the graft holding points 218 could be relocated, replacedwith other gripping features, or eliminated entirely to avoid piercingthe graft vessel 148 at the point of eversion. The graft holding points218 perform one of the functions of the exterior surface features 116 ofthe coupling device 102 shown in FIG. 1 in that they attach the graftvessel 148 to the coupling member 209.

This embodiment of the two-piece anastomosis staple 207 can be appliedwith a slightly modified version of the anastomosis stapling tool 118 ofFIGS. 2, 6 and 7, following the sequence of steps of FIGS. 5A-5G. Theinner tube 124 of the stapling mechanism 119 grasps the anchor member208 by either the ring-shaped frame 210 or the first segment of theattachment legs with the L-shaped legs of the staple retainer. After asmall incision 151 has been made in the target vessel wall 150 at thedesired anastomosis site, the stapling mechanism 119, with the vesselpunch mechanism 120 inserted into the inner lumen 128, is positioned atthe anastomosis site. The anvil 136 of the vessel punch 120 is insertedthrough the incision 151 and drawn back slightly to support the targetvessel wall 150 so that the wire attachment legs 214 can be driven intothe wall 150. The wire attachment legs 214 are then deformed by thestapling mechanism 119 to attach the anchor member 208 to the targetvessel wall 150. The vessel punch 120 is then actuated to form a hole152 through the target vessel wall 150 centered within the ring-shapedframe 210, as described in relation to FIG. 5D. The anchor member 208 isnow attached to the target vessel wall 150 with the ring shaped frame210 centered around the opening in the vessel wall 152, as shown in FIG.17B. In this illustrative embodiment, the wire attachment legs 214 areconfigured so as to only partially penetrate the target vessel wall 150so that they are embedded within the target vessel wall 150 in theirfinal, deployed configuration. This variation of the method may bepreferred for attachment to some types of body tissues as the targetvessel 150. The wire attachment legs 214 may also be pierced through theentire target vessel wall 150 before they are deformed so that theyreside against the interior of the target vessel wall 150, as shown inFIG. 5C.

Once the anchor member 208 is attached to the target vessel 150, thevessel punch mechanism 120 is withdrawn and the graft insertion tool 121with the graft vessel 192 everted over the distal end of the couplingmember 209 is inserted into the inner lumen 128 of the staplingmechanism 119. The graft insertion tool 121 is used to press thecoupling member 209 into the ring-shaped frame 210 of the anchor member208 until the everted end 192 of the graft vessel 148 is firmly sealedagainst the outer surface of the target vessel wall 150 and theretaining clips 216 have seated over the proximal end of the couplingmember 209. The coupling member 209 is held in the ring-shaped frame 210by the retaining clips 216. The graft holding points 218 may be made sothat they penetrate through the graft vessel wall 192 and into thetarget vessel wall 150, as shown in FIG. 17C, to increase the securityof the anastomosis attachment. It should be noted that other sequencesof operations are also possible for this embodiment, such as punchingthe opening in the target vessel wall prior to attachment of the anchormember.

Another embodiment of the two-piece anastomosis staple device 219 isshown in FIGS. 18A-18F. This embodiment of the device lends itself todifferent manufacturing methods than the previously describedembodiments. The anchor member 220 shown in perspective in FIG. 18A canbe formed from a single piece of sheet metal by a combination ofpunching and drawing steps. The anchor member 220 has a plate 221 whichis curved to fit the contours of the exterior surface of the targetvessel wall 150, as seen in the end view FIG. 18B. For performing anaortic anastomosis, the radius of curvature of the plate 221 wouldtypically be between 10 and 20 mm in an adult human. The plate 221 wouldbe approximately 10 to 20 mm in width and 10 to 25 mm in length. Theplate 221 is punched so as to form integral attachment legs 222. Thisillustrative embodiment is shown with four integrally formed attachmentlegs 222, as best seen in top view FIG. 18C. A tubular proximalextension 223 is formed on the curved plate 221 by drawing the sheetmetal plate 221 to form a cylindrical extension 223, then piercing ordrilling it to open the proximal end of the cylinder. A final forming orstamping operation forms a radiused flange 224 at the proximal end ofthe tubular extension 223 that serves as a strain relief to preventsharp bends or kinking of the graft vessel 148 close to the anastomosissite.

This embodiment of the anchor member can be attached to the targetvessel wall by a sequence of operations similar to that described inrelation to FIGS. 5A-5G. Alternatively, the sequence of operations canbe re-ordered so that the target vessel is punched before placement ofthe anchor member similar to that described for the one-piece embodimentof FIG. 9. Thus, either of the anastomosis stapling mechanisms 118. 179previously described could easily be adapted to hold the anchor member208 of FIG. 18 and to drive the attachment legs 222 into the targetvessel wall 150.

The coupling member 225 in this embodiment is a toroidal ring 225 madeof a resilient biocompatible material such as plastic, rubber or aspringy metal having an outside diameter slightly smaller than theinside diameter of the cylindrical extension 223. The coupling member225 is shown in FIG. 18D. The graft vessel 148 is prepared foranastomosis by passing the end of the vessel through the central openingof the toroidal ring 225 and everting it back 192 over the ring, asshown in the FIG. 18E. The ring 225, with the graft vessel 192 evertedover it, is then collapsed or folded enough so that it can be insertedinto the proximal tubular extension 223 of the anchor member 220. Oncethrough the cylindrical extension 223, the toroidal ring 225 recoils toits expanded size, sealing the graft vessel wall 192 against the wall ofthe target vessel 150 and preventing the end of the graft vessel 192from pulling out of the tubular extension 223. Alternatively, acylindrical ring-shaped coupling member with locking features, similarto those shown in FIGS. 1 and 17B, can be used in conjunction with theanchor member of FIG. 18A.

FIGS. 19A and 19B show an alternate construction 226 of the two-pieceanastomosis staple 219 device of FIGS. 18A-18E. In this variation of thedevice, the anchor member 227 may be made from a flat piece of sheetmetal that is punched to form a flange 238 with a central aperture 228and integrally formed attachment legs 229. The anchor member 227 isattached to the target vessel 150 with the central aperture aligned 228with a preformed hole 152 in the wall of the target vessel 150.Alternatively, the anchor member 227 can be placed before the hole 152is punched. The attachment legs 229 are shaped with straight distalsegments, as shown by the phantom lines 231′, that penetrate the targetvessel wall 150 in a linear fashion. A stapling device with a stapledeforming anvil is passed through the hole 152 in the target vessel wall150 to deform the attachment legs 229 so that they grip the targetvessel wall 150, as shown by the solid lines 231. The attachment legs229 can be deformed one at a time or some or all of the attachment legs229 can be deformed at once depending on the design of the staplingdevice. Alternatively, the attachment legs 229 can be precurved anddriven into the target vessel wall 150 from the outside.

The central aperture 228 in the flange 230 of the anchor member 227 hasattachment features that interlock with matching attachment features ona first tubular coupling member 232. As an illustration of one possibleconfiguration, the first coupling member is shown with two pairs of tabs233, 234 extending radially from the distal edge of the first tubularcoupling member 232. One pair of tabs 234 is slightly more distal thanthe other pair 233. The central aperture 228 of the anchor member 227has a matching pair of slots 235 extending from the aperture 228. Thefirst coupling member 232 is joined to the anchor member 227 by aligningthe more distal pair of tabs 234 with the slots 235, pushing the tabs234 through the slots 235, then turning the coupling member 232 untilthe tabs 234 are locked onto the edges of the aperture 228. The firsttubular coupling member 232 may be made with integrally formed graftholding points 236 which are cut and bent inward from the wall of thefirst tubular coupling member 232 to hold the everted graft in place.The graft may be everted over a second tubular coupling member 196,which is inserted into the first tubular coupling member 232 and isattachable to the first tubular coupling member at the proximal ends ofthe tubular coupling members, as shown in FIG. 19B.

FIG. 20 shows a fourth alternate construction 237 of the two-pieceembodiment of the anastomosis staple device 100 of FIG. 1. The anchormember 238 of the anastomosis staple device 237 may be formed from apiece of sheet metal, similarly to the other alternate embodimentspreviously described. The anchor member 238 has a distal plate 239 whichmay be flat or curved to match the exterior curvature of the targetvessel 150. Multiple attachment legs 240 are cut from the plate material239, sharpened at the ends 241, and bent with a first section 242 thatangles upwardly from the plate 239 and a second section 243 that isangled downward to pierce the target artery wall, as shown in phantomlines 243′ in FIG. 20. Preferably, the second section 243 is curved witha radius of curvature approximately equal to the length of the firstsection 242. A tubular proximal extension 244 with a slight hourglassshape extends from the distal plate 239 of the anchor member 238.

The coupling member 245 of the anastomosis staple device 237, shown inFIG. 20, is made in a tubular shape of a biocompatible resilientmaterial such as plastic, rubber or a springy metal, such as anickel-titanium alloy. The tubular coupling member 245 has a slighthourglass shape in axial cross section, matching the interior shape ofthe tubular proximal extension 244 of the anchor member 238. If desired,the tubular coupling member 245 can be made with slightly thickenedproximal 246 and distal 247 extremities which act as 0-rings moldedintegrally with the wall of the tube. The tubular coupling member 245can be made with a continuous tubular wall or with a longitudinal slotin the wall of the tube to increase the resiliency of the couplingmember. Alternatively, the tubular coupling member 245 can be made of acoiled spring with an hourglass shape in axial cross section.

As with the previously described embodiments, the anchor member 238 canbe applied to the exterior of the target vessel 150 either before orafter an opening 152 has been created with a vessel punch. To place theanchor member 238, the plate 239 of the anchor member 238 is pressedagainst the exterior surface of the target vessel 150 at the anastomosissite and the attachment legs 240 are pressed to drive the sharpened tips241 through the target vessel wall 150. If an opening 152 has not yetbeen made in the target vessel wall 150, a vessel punch is insertedthrough the lumen 244 of the proximal tubular extension 244 to create anopening 152 in the wall 150 concentric with the tubular extension 244.

Meanwhile, the graft vessel 148 is prepared by placing it through thelumen of the tubular coupling member and everting the end 192 of thegraft vessel 148 over the outside of the coupling member 245. Tocomplete the anastomosis, the coupling member 245 with the end 192 ofthe graft vessel 148 attached is collapsed or folded and inserted intothe proximal tubular extension 244 of the anchor member 238. Theresilience of the coupling member 245, combined with the matchinghourglass shapes of the two parts of the staple device, locks the partstogether to form a leak-proof anastomosis.

The coupling member 245 can be dimensioned so that the distal end of thecoupling member 245 extends through the opening 152 in the target vesselwall and the everted edge 192 of the graft vessel 148 seals within theopening 152, as illustrated, or against the interior surface of thetarget vessel 150 similarly to the one-piece embodiment of theanastomosis staple device illustrated in FIG. 9.

Alternatively, the coupling member 245 can be shaped so that it pressesthe everted edge 192 of the graft vessel 148 against the exteriorsurface of the target vessel 150 to create a leak-proof seal similar tothe embodiment of FIG. 1.

In a further aspect of the invention, an anastomosis fitting is providedfor rapidly and reliably creating an end-to-side anastomosis between agraft vessel and a target vessel. A first representative embodiment ofan anastomotic fitting 250 according to this second aspect of thepresent invention is shown in FIGS. 21A-21C. The anastomotic fitting 250is made up of two coacting parts: a) a tubular inner sleeve 251 whichhas an internal lumen 252 of sufficient size to accommodate the externaldiameter of the graft vessel 254 and an inner flange 253 which isattached or formed at the distal end of the sleeve 251 so as to bepositioned within the lumen 256 of the target vessel 255, and b) anouter flange 260 which has a central orifice 261 that is sized to fitover the exterior of the inner sleeve 251 to be positioned against theexterior surface 258 of the target vessel wall 255. The anastomoticfitting 250 is thus held in place by compressing the target vessel wall255 between the inner 253 and outer 260 flanges. An adjustable lockingmechanism 262 holds the outer flange 260 on the inner sleeve 251 at aselected position to create a tailored degree of tissue compression atthe anastomotic site. The anastomosis fitting 250 can be made of variousbiocompatible materials, such as stainless steel, titanium alloys,plastic, pyrolvtic carbon, etc. Additionally, biocompatible coatingscould be applied to the inner and/or outer surfaces of the fitting 250to increase its acceptance by the body tissues or to reduce thrombosis.

The inner sleeve 251 is a tubular member with an internal lumen 252large enough to accommodate the external diameter of the graft vessel254, either a natural graft vessel or an artificial graft vessel.Natural saphenous vein autografts typically have an internal diameterbetween 3 mm and 10 mm and an external diameter between 4 mm and 11 mm.Pedicled arterial grafts, such as the internal mammary artery or thegastroepiploic artery typically have an internal diameter between 2 mmand 7 mm and an external diameter between 3 mm and 8 mm, with thicker,more muscular walls. Artificial prosthetic graft vessels, made ofmaterials such as Dacron or Goretex, typically have a diameter of 3 mmto 30 mm. The tubular inner sleeve 251 should be made of a rigidbiocompatible material, such as stainless steel, titanium alloys or arigid biocompatible plastic. The wall thickness of the sleeve ispreferably about 0.2 mm to 2.0 mm.

The distal end of the inner sleeve is flared at an angle ofapproximately 45 to 75 degrees to form a conical inner flange 253. Theinner flange 253 has an outer diameter of approximately 1.3 to 2.5 timesthe inner diameter of the inner sleeve 251. The use of a conical orrounded inner flange 253 helps to improve the hemodynamic efficiency ofthe anastomosis connection by improving the orifice coefficient at theentrance to the graft vessel 254. It also assures that the finishedanastomosis will not protrude into the lumen 246 of the target vessel255 or upset the hemodynamic flow in that vessel. The exterior of thetubular inner sleeve 251 has a series of circumferential ridges 263 orthreads which may be sawtooth in shape.

The outer flange 260 as a central orifice 261 which is sized to fit overthe exterior of the tubular inner sleeve 251. The outer flange 260 hasan outer diameter of approximately 1.3 to 3.0 times the inner diameterof the inner sleeve 251. A ratchet mechanism 264 within or adjacent tothe central orifice 261 of the outer flange 260 engages thecircumferential ridges 263 on the exterior of the tubular inner sleeve251. The ratchet 264 can be strictly a one-way mechanism so that theouter flange 260 can only move in the direction of the inner flange 253or a release mechanism can be incorporated so that the outer flange 260can be moved away from the inner flange 253 in case of prematureactivation of the ratchet mechanism 264. Alternatively, the outer flange260 could be threaded to the exterior of the tubular inner sleeve 251.The distal edge 265 of the outer flange 260 may incorporate a pluralityof attachment spikes 266 that engage and hold the wall of the targetvessel 255 and/or the everted wall 259 of the graft vessel 254 when theouter flange 260 is applied. In the preferred embodiment which isintended for creating an anastomosis between a coronary artery bypassgraft and the ascending aorta, the outer flange 260 has 4 to 12 spikesof 1 to 3 mm length and 0.2 to 0.5 mm diameter. Variations of thisconfiguration may be made where appropriate for different graft vesselsand target vessels.

The anastomosis is performed by passing the end 259 of the graft vessel254 through the inner lumen 252 of the tubular inner sleeve 252 untilthe end of the vessel extends a short distance from the distal end ofthe sleeve, as shown by phantom lines 259′ in FIG. 21A. The end 259 ofthe graft vessel 254 is then everted over the conical inner flange 253of the fitting 250 to form an atraumatic attachment, as shown in FIGS.23A. If desired, a loop of suture can be tied around the everted end 259of the graft vessel 254 to hold it in place on the inner flange 253and/or the tubular inner sleeve 251. The conical inner flange 253 andthe everted end 259 of the graft vessel 254 are then passed through anopening 267 that has previously been made in the wall of the targetvessel 255 with an instrument such as a vessel punch, as shown in FIG.21B. The diameter of the opening 267 in the target vessel wall ispreferably about the same as the external diameter of the tubular innersleeve 251. The opening 267 may need to stretch slightly to allow theconical inner flange 253 to pass through. The elastic recovery of thetarget vessel wall 255 around the opening 267 helps to create ananastomotic seal by contracting around the inner sleeve 251 and theeverted graft vessel wall 259. The outer flange 260 is then slid ontothe proximal end of the inner sleeve 251. If the anastomosis beingperformed is the first anastomosis of a free graft, such as a saphenousvein graft, with the other end of the graft unattached, then the outerflange 260 can be slid over the graft vessel 254 from the free end. Ifthe other end of the graft vessel 254 is not free, such as whenperforming a second anastomosis or a distal anastomosis on a pedicledgraft like the IMA, then the outer flange 260 should be back loaded ontothe graft vessel 254 or preloaded onto the proximal end of the innersleeve 251 before the end 259 of the graft vessel 254 is attached to theinner flange 253 of the fitting 250. The outer flange 260 is slid downthe inner sleeve 251 until it contacts the exterior wall 258 of thetarget vessel 255 and a desired degree of compression of the targetvessel wall 255 is applied between the inner 253 and outer 260 flanges.The ratchet mechanism 264 of the outer flange 260 locks the flange 260in place on the tubular inner sleeve 251 to complete the anastomosis, asshown in FIG. 21C.

FIGS. 22A-22D show an anastomosis fitting 268 which is a variation ofthe embodiment of FIGS. 21A-21C. In this variant the inner flange 269has a flat annular configuration, rather than a conical shape as in thepreviously described embodiment. To insure that the completedanastomosis does not protrude into the blood flow lumen 256 of thetarget vessel 255, the outer flange 270 of the fitting is concave on itsdistal surface 271. The central orifice 272 of the outer flange 270tapers proximally to a locking ring 273 within the central orifice 272that slips over and locks with a collar 274 on the proximal end of thetubular inner sleeve 275. As shown in FIG. 22C, when the outer flange270 is applied to the exterior surface 258 of the target vessel 255 andlocked onto the collar 274 of the tubular inner sleeve 275, the innerflange 269 is drawn into the concave outer flange 270, so that theanastomosis is flush with or recessed into the inner wall 257 of thetarget vessel 255. This helps to assure a hemodynamically correct inflowat the entrance to the graft vessel 254. Two or more collars 274 may beprovided on the tubular inner sleeve 275 to allow adjustable compressionby the anastomotic fitting 268.

FIGS. 23A-23D show another variant 276 of the embodiment of theanastomosis fitting of FIGS. 21A-21C and FIGS. 22A-22D. In this variantthe concave outer flange 277 has a simple central orifice 278 without alocking ring. The locking mechanism is provided by multiple downwardlyoriented tangs 279 or tapered ridges, which have been formed in thesidewall of the tubular inner sleeve 280 by cutting, punching ormolding. The outer flange 277 is slid over the proximal end of the innersleeve 280 and over the tangs 279, which engage the proximal end of theouter flange 277 to lock the outer flange 277 into place on the innersleeve 280, as illustrate in FIG. 23C. If desired, multiple parallelrows of tangs 279 can be provided at different axial locations on theinner sleeve 280 to accommodate different thicknesses of the targetvessel wall 255 and to provide a tailored degree of tissue compressionat the anastomosis site. Optionally, the underside of the outer flange277 may have a plurality of attachment points which engage and hold thetarget vessel wall 255 near the opening 267 in it, adding security tothe anastomosis attachment without piercing the target vessel wall 255.

FIGS. 23A-23D also illustrate a variation of the method for applying theanastomosis fitting. In this embodiment, the method includes applying asuture 281 to the everted end 259 of the graft vessel 254 to secure itto the inner flange 282. As best seen in the top view FIG. 23D, theeverted end 259 of the graft vessel 254 has been secured to the innerflange 282 of the fitting by making a running stitch around the end ofthe graft vessel with a suture 281 on the back of the inner flange 282and tying it to create a purse string that holds the end 259 of thegraft vessel 254 in place.

A second representative embodiment of an anastomotic fitting 283employing inner 284 and outer 285 flanges has an expanding inner flange284 which facilitates the atraumatic attachment of the graft vessel 254to the fitting 283 and makes it easier to pass the inner flange 284 andthe everted graft vessel 259 through the opening 267 in the targetvessel wall 255. Two variations of such an expanding inner flange areshown in FIGS. 24A-24D and FIGS. 25A-25H. The graft vessel 254 is passedthrough an internal lumen 287 of an inner sleeve 286 which has theexpandable inner flange 284 attached at its distal end. The end 259 ofthe graft vessel 254 is everted over the unexpanded inner flange 284′.The inner flange 284′ and the everted end 259 of the graft vessel 254are passed through the opening 267 in the target vessel wall 255. Oncethe inner flange 284′ of the fitting 283 is in the lumen 256 of thetarget vessel 255, it is expanded to a diameter 284 which issignificantly larger than the opening 267 in the target vessel wall 255.Then an outer flange 285 is applied and locked into a selected positionon the inner sleeve 286 as described above to complete the anastomosis.

In the first variant of the expanding inner flange 284, shown in FIGS.24A-24D, the flange 284 and a portion of the inner sleeve 286 areslotted to create multiple fingers 288 which are initially collapsedinward toward the center of the inner sleeve 286. The ends of thefingers form sector-shaped sections 289 of the flange 284, as seen inthe distal end view of FIG. 24D. When the flange 284 is collapsed inward284′, as in FIG. 24C, the sectors 289 fit together to form a smallerdiameter flange 284′ with a passage 287′ through the center large enoughfor a collapsed graft vessel 254 to fit through. A tubular former 290 isslidably received within the slotted inner sleeve 286 and has an axiallumen 291 large enough to receive the graft vessel 254. The tubularformer 290 initially resides in a proximal position, as shown in FIG.24A. The tubular former 290 has a ridge 292 at its proximal end thatpositions the tubular former 290 in the correct location with respect tothe inner sleeve 286 when the tubular former 290 is in its distal,deployed position. An outer flange 285, with a concave distal surface293 may be permanently attached to the inner sleeve 286 proximal to theexpanding inner flange 284. Alternatively, the outer flange 285 can beprovided as a separate component which is attached to the inner sleeve286 after the graft vessel 254 has been attached or at the end of theanastomosis procedure.

In operation, the graft vessel 254 is inserted through the axial lumen291 of the tubular former 290 and through the internal lumen 287 of theslotted inner sleeve 286 and through the central opening 287′ betweenthe collapsed sectors 289′ of the inner flange 284′. The end 259 of thegraft vessel 254 is everted over the collapsed sectors 289′ of theflange 284′. The collapsed flange 282′ and the everted end 259 of thegraft vessel 254 are inserted through the opening 267 in the targetvessel 255. Then, the tubular former 290 is slid distally within theslotted inner sleeve 286. The tubular former 290 forces the fingers 288outward, expanding the flange 284 within the target vessel 255. If theouter flange 285 is already attached to the inner sleeve 286 at thispoint, the distal surface 283 of the outer flange 285 is pressed againstthe exterior surface 258 of the target vessel 255 as the expandableinner flange 284 is being deployed to complete the anastomosis. If, onthe other hand, the outer flange 285 has been supplied as a separatecomponent, the outer flange 285 is slipped over the proximal end of theinner sleeve 286 after the expandable inner flange 284 has been deployedand a desired degree of tissue compression is applied between the inner284 and outer 285 flanges of the fitting 283 to complete theanastomosis, as shown in FIG. 24B.

A second variant of the anastomotic fitting 294 with an expanding innerflange 298 is shown in FIGS. 25A-25H. The inner sleeve 295 of thefitting 294 is slotted along its entire length to form multiple fingers296 that are oriented essentially longitudinally to the inner sleeve295. A collar 297 on the proximal end of the slotted inner sleeve 295joins the multiple fingers 296 together in a tubular configuration. Aconcave outer flange 299 is captured on the slotted inner sleeve 295 bythe proximal collar 297. As seen in the end view in FIG. 25E, the insidediameter of the collar 297 has notches 301 which are extensions of theslots 300 between the fingers 296 of the inner sleeve 295. Each of thefingers 296 has a bend 302 in it to predispose it to bend outward at themiddle when contracted longitudinally. A tubular forming tool 303 forexpanding the inner flange 298 is slidably received within the slottedinner sleeve 295. The distal end of the tubular forming tool 303 iscrenellated with multiple radially extending tabs 304. The multipleradially extending tabs 304, as seen in the end view in FIG. 25F, areconfigured to fit through the notches 301 in the collar 297 and into theslots 301 of the inner sleeve. The tubular forming tool 303 is insertedinto the slotted inner sleeve 295 by aligning the radially extendingtabs 304 with the notches 301 in the collar 297 and sliding it distallyalong the slots 300 until the tabs 304 pass the distal ends 305 of thefingers 296. Then, the tubular forming tool 303 is rotated slightly sothat the radially extending tabs 304 engage the distal ends 305 of thefingers 296 of the slotted inner sleeve 295, as shown in FIG. 25A.

The anastomosis is performed by passing the graft vessel 254 through theinternal lumen of the forming tool 303 within the slotted inner sleeve295 and everting it 259 over the distal ends 305 of the fingers 296. Aloop of suture 306 can be used to hold the everted vessel 259 in place.The fingers 296 of the fitting 294 and the everted end 259 of the graftvessel 254 are inserted through an opening 267 in the target vessel wall255. When the tubular forming tool 303 is slid proximally with respectto the slotted inner sleeve 295, the radially extending tabs 304 of thetubular forming tool 303 bear against the distal ends 305 of the fingers296 compressing them longitudinally. The fingers 296 bow outward,folding at the bend 302 to expand and create an inner flange 298 whichengages the inner surface 257 of the target vessel wall 255. The tubularforming tool 303 is pulled further proximally until the newly formedinner flange is drawn into the concave outer flange 299, compressing thetarget vessel wall 255 and recessing the inner flange 298 and theanastomotic connection into the target vessel wall 255, as shown in FIG.25D. The tubular forming tool 303 can now be removed by rotating it withrespect to the slotted inner sleeve 295 so that the tabs align with theslots 300 and withdrawing it from the fitting 294. The mass of foreignmaterial that is left as an implant at the anastomotic site is thusreduced.

Alternatively, the inner sleeves 295 and the tubular forming tool 303can be formed integrally or welded together as one piece, in which caseboth the inner sleeve 295 and the tubular forming tool 303 would remainin the finished anastomosis. As a further alternative, the tubularforming tool 303 could be made to break away from the inner sleeve 295when a certain force is applied.

In a further aspect of the invention, the anastomotic fitting has asingle-piece construction with an inner sleeve that is integrallyattached to a fixed inner flange and to a deformable outer flange. Threevariants of the anastomotic fitting with a deformable outer flange andtheir forming tools are shown in FIGS. 26A-26I, 27A-27D and 28A-28I.

The first variant of the anastomotic fitting 306 with a deformable outerflange is shown in FIGS. 26A-26I. The anastomotic fitting 306 has atubular main body 307 having an internal lumen 303 sized to accommodatethe external diameter of the graft vessel 254. A fixed inner flange 309is attached to the distal end of the tubular body 307. On the proximalend of the tubular body 307 are a plurality of hingedly attached outerflange segments 310. In this illustrative embodiment, there are foursuch flange segments 310 which are enlarged at their outer edges to formsector-shaped segments 310 of the outer flange 311. The hinge portion312 of each flange segment 310 is a deformable strip of metal 312connecting the flange segment 310 to the main tubular body 307.Preferably, the tubular body 307, the inner flange 309 and the flangesegments 310 of the outer flange 311, including the deformable hingeportion 312, are integrally formed of a single piece of biocompatiblemetal, such as stainless steel, a titanium alloy or a cobalt alloy (e.g.Carpenter MP35).

The distal end of a device 313 for applying the anastomosis fitting isshown in FIG. 26B. The device has an inner tubular member known as theanvil 314 and an outer tubular member called the driver 315. The distalend of the anvil 314 has a gripper 316 for holding onto the anastomosisfitting 306. The gripper 316 in the preferred embodiment has abeyonet-type fitting with four L-shaped gripping fingers 317 which holdthe fitting 306 by hooking onto each of the flange segments 310 at thedeformable hinge portion 312. The driver slides 315 telescopically overthe outside of the anvil 314 and has an annular driving surface 318 onits distal end configured to engage the outer ends of each flangesegment 310. The anvil 314 and the driver 315 can be made in a longversion, approximately 15 to 30 cm in length, for performing port-accessCABG surgery or a short version, approximately 10 to 20 cm in length,for performing standard open-chest CABG surgery.

The fitting 306 is prepared for performing the anastomosis by attachingthe fitting 306 to the gripper 316 on the distal end of the anvil 314.Then, the graft vessel 254 is passed through the inner lumen 319 of theanvil 314 until the end 259 to be anastomosed extends a short distancefrom the distal end of the fitting 306. The end of the graft vessel 259is everted over the inner flange 309 of the fitting to form anatraumatic attachment between the two. If the anastomosis beingperformed is part of a port-access CABG surgery procedure, the fittingon the end of the application tool is inserted into the patient's chestthrough an access port made through one of the intercostal spaces. Theinner flange 309 and the everted end 259 of the graft vessel 254 areinserted through an opening 267 that has been made in the wall of thetarget vessel 255. The fitting 306 is pulled back slightly so that theinner flange 309 is flush against the interior surface 257 of the targetvessel. Then, the driver 315 is pushed distally with respect to theanvil 314 until the driving surface 318 deforms the outer flangesegments 310 against the exterior surface 258 of the target vessel wall255 and the desired degree of compression of the vessel wall 255 isobtained. The anvil 314 is rotated slightly to release the gripper 316from the flange segments 310 of the fitting 306 and the applicationdevice 313 is withdrawn from the patient's body.

The second variant of the anastomotic fitting 320 with a deformableouter flange 321 is shown in FIGS. 27A-27D. This variant is largely thesame as the first variant just described in connection with FIGS.26A-26I with the exception of the inner flange 322 construction. In thisembodiment, the inner flange 322 is slightly conical in order to providea more hemodynamically efficient inlet to the graft vessel 254 at theanastomosis. In addition, a plurality of attachment spikes 323preferably 6 to 8 spikes, have been provided along the periphery of theinner flange 322. In a preferred configuration, the anastomotic fitting320 is fully deployed, the spikes 323 penetrate through the everted wall259 of the graft vessel 254 and into the wall of the target vessel 255to create a more secure attachment for the anastomosis. When the outerflange segments 324 are deformed against the exterior surface 258 of thetarget vessel 255 and compress the vessel wall 255 such that they engagethe spikes 323 on the inner flange 322 for a very secure attachment.

The third variant of the anastomotic fitting 325 with a deformable outerflange 326 is shown in FIGS. 28A-28I. The anastomotic fitting 325 has atubular main body 327 with an internal lumen 328 sized to accommodatethe external diameter of the graft vessel 254. The walls of the tubularbody 327 have a pair of L-shaped slots 329 that are open at the top ofthe tubular body 327 to form a beyonet fitting. An inner flange 330,which may be slightly conical in shape, is attached to the distal end ofthe tubular body 327. Attached to the proximal end of the tubular body327 is a deformable outer flange 326, comprising a multiplicity ofaxially-oriented bars 331 separated by axial slots, 332 Theaxially-oriented bars 331 are attached at their distal ends to thetubular main body 327, and are joined at their proximal ends by a ring333 forming the proximal end of the fitting 325 The bars 331 are bentoutwardly near their centers 334 so that the bars 331 preferentiallybend outwardly when compressed. The tubular body 327, the inner flange330 and the deformable outer flange 326 are preferably machined of asingle piece of biocompatible metal, such as stainless steel, a titaniumalloy or a cobalt alloy. The geometry of this device could also beconfigured so that the bars 331 of the outer flange 326 start off almoststraight, and are deformed further to reach their final geometry.

A device 335 or applying the anastomotic fitting is shown in FIG. 28D-F.The device 335 has an inner tubular member 336 which has a pair ofradially extending tabs 337 on its distal end that interlock within theL-shaped slots 329 in the tubular body 327 of the fitting 325. An outertubular member 338, the pusher 338, slides telescopically over theoutside of the inner tubular member 336 and has an annular drivingsurface 339 on its distal end. This anastomosis fitting applicationdevice 335 can be made in a long version for port-access CABG surgery ora short version for standard open-chest CABG surgery.

The fitting 325 is prepared for performing the anastomosis by attachingthe anastomotic fitting 325 to the inner tubular member 336. Then, thegraft vessel 154 is passed through the inner lumen 340 of the innertubular member 336 until the end 159 to be anastomosed extends a shortdistance from the distal end of the fitting 325. The end 159 of thegraft vessel 154 is everted over the inner flange 330 of the fitting 325to form an atraumatic attachment, as shown in FIG. 28D. If theanastomosis being performed is part of a port-access CABG surgeryprocedure, the fitting 325 on the end of the application tool 335 isinserted into the patient's chest through an access port made throughone of the intercostal spaces. The inner flange 330 and the everted end159 of the graft vessel 154 are inserted through an opening 267 that hasbeen made in the wall of the target vessel 225, as shown in FIG. 28E.The fitting 325 is pulled back slightly so that the inner flange 330 isflush against the interior surface 257 of the target vessel 255. Then,the pusher 338 is moved distally with respect to the inner tubularmember 336 until the driving surface 339 contacts the proximal surfaceof the deformable outer flange 326. The pusher 338 deforms the outerflange 326 by compressing the bars 331, which bend outwardly and foldinto a flattened configuration, as shown in FIG. 28F, to form a radiallyspoked outer flange 326′. The pusher 338 further deforms the bars 331 topress the outer flange 326′ against the exterior surface 258 of thetarget vessel wall 255 and obtain the desired degree of compressionbetween the inner 330 and outer 326′ flanges. The inner tubular member336 is removed by rotating it with respect to the fitting 325 andwithdrawing the tabs from the L-shaped slots 329.

A further embodiment of an anastomosis fitting 340 according to theinvention is illustrated in FIG. 29A-C. The anastomosis fitting of FIG.29A-C may be particularly advantageous with older patients, diabeticpatients and other patients whose veins are no longer as resilient asthey once were, where it may be difficult to stretch the saphenous veingraft enough to evert it over a large inner flange. This is also true ofmany artificial graft materials that will not stretch at all to evertthem over a large flange. The anastomosis fitting 340 of FIG. 29A-C hasa tubular body member 341 with a small primary inner flange 342 attachedto the distal end. Threads 343 or similar features on the inner surfacethe proximal end of the tubular body member 341 facilitate grasping thetubular body member 341 with an application instrument. A secondaryinner flange washer 344 has a central orifice 345 with inwardly facingtabs 346 configured to engage the primary inner flange 342, as seen indistal end view 29C. An outer flange 347 is configured to slide over theproximal end of the tubular body 341 and is locked in place by aself-locking retaining washer 348 with upwardly inclined tabs 349 thatfrictionally engage the outer surface of the tubular body 341, allowingthe outer flange 347 to slide in the distal direction with respect tothe tubular outer body 341, but not in the proximal direction. The outerflange 341 may have a plurality of attachment spikes 350 on its distalsurface to penetrate the outer wall 258 of the target vessel 255.

In operation, first the outer flange 347 with its retaining washer 348and then the secondary inner flange washer 344 are back loaded onto theholder 352 of the application device 351. Next, the tubular body 341 isthreaded onto the distal end of the holder 352. The graft vessel 254 ispassed through the internal lumen 353 of the application instrument 351and the distal end 259 of the graft vessel 254 is everted over the smallprimary inner flange 342 of the anastomosis fitting 340. The secondaryinner flange washer 344 is then slid distally so that it bears againstthe proximal face of the inner flange 342, as shown in FIG. 29A. Theprimary inner flange 342, with the everted graft vessel 259 attached,and the secondary inner flange washer 344 are inserted through anopening 267 that has been made in the target vessel wall 255 as shown inFIG. 29A. A slight tension is exerted on the application instrument 351to seat the primary inner flange 342 and the secondary inner flangewasher 344 against the interior surface 257 of the target vessel wall255 and the driver 354 is advanced distally to press the outer flange347, with its self-locking retaining washer 348, onto the exterior ofthe tubular body member 341 until the desired degree of compressionbetween the inner 242, 344 and outer flanges is obtained. The holder 352is disengaged from the tubular body member 341 and the entireapplication instrument 351 is withdrawn from the body.

A distal end view of the completed anastomosis is shown in FIG. 29C. Thelarger diameter of the secondary inner flange washer 344 adds to thesecurity of the anastomosis attachment, while it does not require thegraft vessel 254 to be stretched to fit over a large inner flange. Onlya very small amount of foreign material is exposed within the targetvessel lumen and it is spaced a short distance from the actualanastomosis site which may reduce the likelihood of complications.Because the secondary inner flange 344 washer only contacts the primaryinner flange 342 and the everted graft vessel wall 259 at four smallpoints, it will not interfere with the intima-to-intima approximation ofthe graft vessel 259 and the target vessel 255 which is preferred inorder to promote endothelialization of the anastomosis site.

FIGS. 30A-30F illustrate an embodiment of the anastomosis fitting 355 ofthe present invention which combines an inner tubular member 356 havingdeformable attachment legs 357 at its distal end, with an outer flange358. The deformable attachment legs 357 have an initial position 357allowing the graft vessel 254 to be easily everted over and penetratedby the attachment legs 357. The attachment legs 357 are subsequentlydeformed to a deployed position 357′ wherein the attachment legs 357′perform the function of the inner flange in many of the above-describedembodiments by engaging the interior surface 257 of the target vessel255 and compressing the tissue between the attachment legs 357′ and theouter flange. 358 The inner tubular member 356 is shown in FIG. 30A. Thetubular member 356 is preferably made from a biocompatible metal, suchas an alloy of stainless steel, titanium or cobalt. The tubular member356 has an internal lumen 359 of sufficient size to accommodate theexternal diameter of the graft vessel 254. The tubular member 356 ismade with a plurality of attachment legs 357 extending axially from itsdistal end 360. This illustrative embodiment is shown with fourattachment legs 357. Other exemplary embodiments may have from three totwelve attachment legs 357 depending on the sizes of the graft vessel254 and target vessel 255 to be joined. The attachment legs 357preferably have a width of approximately 0.5-2.0 mm, more preferablyabout 1.0 mm, and a thickness of approximately 0.1-0.5 mm, morepreferably about 0.2 mm. The width and thickness of the attachment legs357 is chosen so that the legs 357 will be relatively rigid when theyare in their deployed position 357′, yet they are still easily deformedusing the special forming dies 369, 370, 371 provided with theanastomosis system. The distal ends 361 of the attachment legs 357 aresharpened to easily penetrate the walls of the graft vessel 254 andtarget vessel 255. The exterior surface of the tubular member 256 may bemade with a groove or slot 362 around its circumference as a detent forthe outer flange 358 spaced a calculated distance from the distal end360 of the tubular member 356 to provide a desired degree of compressionon the anastomosis when the outer flange 358 locks into the groove. 362A plurality of holes 363 through the wall of the tubular member 356(three holes 363 in this illustrative embodiment) are located near theproximal end of the tubular member 356 to facilitate grasping the device355 with an application instrument 372.

The outer flange 358, illustrated in FIG. 30B, has a central orifice 364which is sized to fit over the exterior of the tubular member 356. Theouter flange 358 has a locking mechanism, which includes a self-lockingretaining washer 365 with upwardly inclined locking tabs 366 integrallyformed with the outer flange, 358 to slidably position the outer flange358 on the exterior surface of the tubular member 356. Alternatively,the self-locking retaining washer 365 can be manufactured separately andattached to the outer flange 358 The upwardly inclined locking tabs 366allow the retaining washer 365 to slide in the distal direction over theexterior of the tubular member 356, but resist sliding in the proximaldirection. When the upwardly inclined locking tabs 366 lock into thegroove 362 in the exterior surface of the tubular body 356 it forms amore permanent attachment, strongly resisting movement in the proximaldirection. Other locking mechanisms can also be used for positioning theouter flange 358 with respect to the tubular member 356, such as ratchetmechanisms, detents, or releasable locking devices. The distal surface367 of the outer flange 358 is configured to contact the exteriorsurface 258 of the target vessel 255. Preferably, the distal surface 367of the outer flange 358 is slightly concave, as illustrated. If desired,the outer flange 358 may be made with short spikes extending from itsdistal surface. The outer periphery of the outer flange 358 isperforated with a series of holes 368, which are positioned to bealigned with the distal ends 361′ of the attachment legs 357′ of thetubular member 356 when the fitting 355 is fully deployed. Making theholes 368 in a multiple of the number of attachment legs 357, as in thepresent example which has eight holes 368, corresponding with fourattachment legs 357, facilitates aligning the holes 368 with the distalends 361′ of the attachment legs 357′. The outer flange 358 ispreferably made from a biocompatible metal, such as an alloy ofstainless steel, titanium or cobalt or a biocompatible polymer.Alternatively, a separate locking washer 365 made from a biocompatiblemetal can be joined to an outer flange 358 made of a polymer or otherbiocompatible material.

The anastomosis fitting 355 is part of a complete anastomosis system forforming and applying the anastomosis fitting 355 to create anend-to-side anastomosis. A set of three forming dies 369, 370, 371 areconfigured to deform the attachment legs 357 of the anastomosis fitting355 from their initial position 357 to a deployed position 357′, and aspecialized grasping tool 372 is used to insert the deployed innertubular member 356 through an opening 267 in the side wall of the targetvessel 355. These tools, which will be described in more detail in theoperational description below, facilitate the rapid and repeatabledeployment of the anastomosis fitting 355 with a minimum of manualmanipulation required.

In operation, the end-to-side anastomosis procedure is performed usingthe anastomosis fitting 355 by first preparing the free end 259 of thegraft vessel 254 for attachment. If the anastomosis being performed is asecond anastomosis or is being, performed on the free end of a pedicledgraft, the outer flange 358 must first be backloaded onto the graftvessel 254 with the distal surface 367 facing the end 259 of the vesselto be attached. If the anastomosis is being performed as the firstanastomosis on a free graft, the outer flange 358 can be backloaded ontothe graft vessel 254 at this time or it can be passed over graft vessel254 from the far end at a later point in the procedure, whichever ispreferable. Next, the free end 259 of the graft vessel 254 is passedthrough the internal lumen 359 of the inner tubular member 356 so thatit extends a short distance from the distal end 360 of the tubularmember 356, as shown in FIG. 30C. The free end 259 of the graft vessel254 is everted and the attachment legs 357 are pierced through theeverted wall 259 of the graft vessel 254 to prepare the graft vessel 254as shown in FIG. 30D. If desired, a loop of suture can be tied aroundthe everted end 259 of the graft vessel 254 to help secure the graftvessel 254 in its everted position over the exterior surface of thetubular member 356.

After piercing the graft vessel wall 259, the attachment legs 357 of thetubular member 356 are deformed from their axially extending position357 by first bending them outward so that they extend radially from thedistal end 360 of the tubular member 356, then bending the distal ends361′ of each of the attachment legs 357′ so that they are directedproximally with respect to the tubular member 356, as shown in FIG. 30E.For a typical application of the anastomosis fitting 355 in making anend-to-side anastomosis between a saphenous vein graft and the ascendingaorta, the radially extending portion 373 of each deployed attachmentleg 357′ is about 3-4 mm long, and the proximally directed distalportion 374 of each deployed attachment leg 357′ is about 2-5 mm long.These dimensions will vary somewhat depending on the size and the wallthickness of the graft vessel and the target vessel to be joined.

A set of three forming dies 369, 370, 371 are provided for rapidly andrepeatably forming the anastomosis fitting 355 into the deployedposition shown in FIG. 30E. The first die 369 is cylindrical in shapewith a counterbored recess 375 on one end which is sized to hold theproximal end of the tubular member 356 of the anastomosis fitting. Anannular forming surface 376 on the end of the die 369 surrounds thecounterbored recess 375. An annular space 377 between the counterboredrecess 375 and the annular forming surface 376 provides sufficientclearance for the everted end 259 of the graft vessel 254 when the innertubular member 356 of the anastomosis fitting 355 is inserted into thecounterbored recess 375. The proximal end of the graft vessel 354extends through a central lumen 378 in the first die 369 and exits thedie through a notch 379 in the far end of the die 369 which communicateswith the lumen 378. The second die 370 has a conically tapered end 380which is used to initiate the outward bend of the attachment legs 357 bypressing the tapered end 380 between the attachment legs 357, as shownin FIG. 30G. The third die 371 is cylindrical in shape with acounterbore 381 on one end that is sized to fit over the outside of thefirst die 369 with a radial clearance sufficient for the thickness ofthe attachment legs 357′. There is a forming shoulder 382 within thecounterbore 381 of the third die 371, and there is a tapered edge 383leading into the counterbore 381. The third die 371 is placed over thedistal end of the inner tubular member 356 after the attachment legs 357have been bent outward by the second die 370. As the counterbore 381 ofthe third die 371 slides over the exterior of the first die, 369 theradially extending portion 373 of the attachment legs 373 are formedbetween the forming shoulder 382 of the third die 371 and the annularforming surface 376 of the first die 369 and the proximally extendingportion 374 of the attachment legs 357′ is formed between the exteriorof the first die 369 and the counterbore 381 of the third die 371, asshown in FIG. 30H.

The tubular member 356 of the anastomosis fitting 355, which has beenformed to its deployed position, is withdrawn from the first die 369 andis grasped with the special grasping tool 372. The grasping tool 372 hasexpandable jaws 384, 385 which fit between the graft vessel 354 and theinner lumen 359 of the tubular member 356. The jaws 384, 385 are shapedlike sectors of a cylinder with an exterior diameter approximately equalto the inner diameter of the tubular member 356. Each of the sectors issomewhat smaller than a semi-cylinder so that the jaws 384, 385 can becollapsed small enough to easily fit within the internal lumen 359 oftubular member 357. A thumbscrew, or other suitable mechanism, on thegrasping tool 372 expands the jaws 384, 385 so that they bear againstthe interior surface of the tubular member 356. Lugs 386 correspondingto the three holes 363 in the proximal end of the tubular member 356engage the three holes 363 to enhance the grasping tool's grip on thetubular member 356.

Using the grasping tool 382, the bent attachment legs 357′ and thedistal end 360 of the tubular member, with the everted end 259 of thegraft vessel 254 attached, are inserted through an opening 267 in thetarget vessel wall 255 that has previously been made with an aorticpunch or similar instrument, as shown in FIG. 30I. The opening 367 ispreferably made so that it is approximately the size of the externaldiameter of the tubular member 356 to provide compression around theeverted end 259 of the graft vessel 254 to help create an anastomoticseal. Since the opening 267 is slightly smaller than the diameter of thebent attachment legs 357′, the opening 267 must be stretched slightly toallow the attachment legs 357′ to pass through the opening 267.Insertion can be effectively accomplished by passing two of theattachment legs 357′ through the opening 267 in the target vessel wall255, then gently stretching the opening 267 with forceps to insert theremaining attachment legs 357′.

Once the attachment legs 357′ have been passed through the opening 267in the target vessel wall 255, the inner tubular member 356 is pulledback with enough force to cause the sharpened distal ends 361′ of theattachment legs 357′ to pierce the interior surface 257 of the targetvessel wall 255. This action also serves to approximate the everted end259 of the graft vessel 254 with the interior surface 257 of the targetvessel 255 to effect the desired intimal surface-to-intimal surfaceapproximation between the two vessels. The sharpened distal ends 361′ ofthe attachment legs 357′ can be assisted in piercing the target vesselwall 255 by pressing on the exterior 258 of the target vessel wall 255with an elastomeric-tipped probe while maintaining some tension on thetubular body 356 of the fitting using the grasping tool 372. Theanastomosis is completed by sliding the central orifice 364 of the outerflange 358 over the exterior surface of the tubular member 356 andmoving the outer flange 358 distally while keeping some tension on thetubular member 356 to create tissue compression at the anastomosis siteto assure an anastomotic seal. A probe 387 with a distal pushing surface388 can be used to press the outer flange 358 onto the tubular member356. The distal pushing surface 388 of the probe 387 is slotted andangled so that it can be used from the side of the grasping tool 372.The proximally directed distal ends 361′ of the attachment legs 357′pass through the holes 363 around the periphery of the outer flange 358,as shown in FIG. 30J. If desired, the distal surface 367 of the outerflange 358 can be made somewhat concave to help create a hemodynamicallyefficient transition between the target vessel lumen 256 and the graftvessel lumen 249. The self-locking retaining washer 365 of the outerflange 358 locks into the circumferential groove 362 on the exterior ofthe tubular member 356 to permanently hold the outer flange 358 in afixed position relative to the tubular member 356.

FIG. 31A shows a further embodiment of an anastomosis device 390according to the invention that combines a fastening flange 391 with aplurality of staple members 392. The device 390 includes a fasteningflange 391 which has a central orifice 393 of sufficient size toaccommodate the external diameter of the graft vessel 254. The externaldiameter of a saphenous vein graft used in CABG surgery can range from 3to 10 mm. The fastening flange 391 and the central orifice 393 can bemade circular, as shown in FIG. 31B, for making a typical right angleanastomosis. Alternatively, the fastening flange 391 and/or the centralorifice 393 can be made elliptical, oval, egg-shaped or tear dropshaped, as shown in FIGS. 31C and 31D, for making a more hemodynamicallyefficient angled Anastomosis. Many of the anastomotic fittings andstaples described herein lend themselves to noncircular configurations,such as elliptical or teardrop shapes. Each of the detailed descriptionsof the various embodiments should be assumed to include noncircularflanges as an optional configuration. The fastening flange 391 is madewith a distal surface 394 over which the free end 259 of the graftvessel 254 is everted, as shown in FIG. 31A. The fastening flange 391can be made with an annular ridge 395 or with other features on itsouter surface to help attach the everted end 259 of the graft vessel 254to the flange 391. The distal surface 394 of the fastening flange 391may be contoured to provide a close fit between the everted edge 259 ofthe graft vessel 254 and the exterior wall 258 of the target vessel 255.If the target vessel 254 diameter is very large compared to the diameterof the graft vessel 254, as in a coronary artery bypass graft toascending aorta anastomosis, then a planar distal surface 394 on thefastening flange 391 may sufficiently approximate the exterior surface258 of the target vessel 255. However, if the graft vessel 254 diameteris closer to the diameter of the target vessel 255, as in a bypass graftto coronary artery anastomosis, then the fastening flange 391 should bemade with a cylindrical or saddle-shaped contour on the distal surface394 that closely approximates the exterior contour of the target vessel255. The fastening flange 391 should be made of a biocompatible materialsuch as stainless steel, titanium alloys, or a biocompatible polymer.The fastening flange 391 acts as an external stent which holds theanastomosis site open and patent, so the flange material is preferablyrigid or at least sufficiently resilient to hold its intended shape.

The fastening flange 391 with the everted end 259 of the graft vessel254 attached to it is fastened to the exterior wall 258 of the targetvessel 255 with the central orifice 393 aligned with an opening 267 inthe target vessel wall 255 that has been previously made using a vesselpunch or similar instrument. The fastening flange 391 is held in placeby a plurality of fastening members 292, which in this embodiment takethe form of metallic surgical staples 292 which are shown in FIG. 31E.The surgical staples 292, preferably 4-12 of them arranged around theperiphery of the fastening flange 391, traverse from the proximal side396 to the distal side 394 of the flange 391, then pierce the evertedgraft vessel wall 259 and the wall of the target vessel 255. It ispreferable that the staples 292 pass through premade holes 397 in thefastening flange 391, however, if the fastening flange 391 is made of aresilient material, the staples 392 may pierce the flange 391 as theypass through it. The distal ends 398 of the staples 392 are deformed bya forming device or anvil against the interior surface 257 of the targetvessel wall 255 to hold the device in place to complete the anastomosis.

The staples 392 can be specially constructed so that they will deform atthe appropriate point on the attachment legs 399. One way to achievethis desired result is to make the core 400 of the staple 392, includingthe crossbar 401 and the two attachment legs 399, of a soft deformablemetal such as annealed stainless steel. A proximal portion of each ofthe attachment legs 399 is surrounded by a stiffening sleeve 402 that ismade of a more rigid material, such as hard stainless steel hypodermictubing. The stiffening sleeves 402 prevent the proximal portion of theattachment legs 392 from deforming. The stiffening sleeves 402 should besized so that their length corresponds to slightly less than thecombined thickness of the flange 391, the graft vessel wall 259 and thetarget vessel wall 255 so that, when the attachment legs 399 are bent atthe distal edge of the stiffening sleeves 402, a tailored amount ofcompression is applied at the anastomotic site to ensure a leak proofattachment without excessive crushing of the tissue which could lead tonecrosis. Alternatively, the staples could be manufactured withattachment legs 399 having a thicker cross section proximal portion anda thinner cross section distal portion so that the attachment legs 399will deform at the appropriate point.

The anastomosis device 390 is part of a complete anastomosis system thatincludes a specially adapted application device 403 for creating theanastomosis. The distal end of the application device 403 can be seen inFIG. 31A. A staple driver 404 pushes the staples 392 from the proximalend, while a specially constructed anvil 405 reaches into the lumen 256of the target vessel 255 to deform the distal ends 398 of the attachmentlegs 399. The staple driver 404 has an annular distal surface 406 whichpresses against the crossbars 401 of the staples 392. In one embodiment,the staple driver 404 can be tubular with an internal lumen 407 largeenough to accommodate the graft vessel 254, allowing the graft vessel254 to be passed through the staple driver 404 from the proximal end tothe distal end. Alternatively. the staple driver 404 can be made with aC-shaped cross section with a side opening that is large enough to passthe graft vessel through from the side. The anvil 405 is articulated onthe distal end of an elongated shaft 408. The shaft 408 is long andnarrow enough to pass through the lumen 249 of the graft vessel 254 fromthe free end of the graft. The anvil 405 is passed through the graftvessel lumen 249 in an orientation axially aligned with of the shaft 408and, once it is in the lumen 256 of the target vessel 255, it isarticulated at 90°, as shown in FIG. 31A. A cylindrical or olive-shapedcentering element 409, such as an inflatable centering balloon on theshaft 408, can be used to center the shaft 408 of the anvil 405 withinthe lumen 249 of the graft vessel 254 and within the central orifice 393of the flange 291. The anvil 305 can now be rotated about the shaft 308to deform the distal ends 398 of the attachment legs 399.

The application device 403 can operate by two different mechanisms. Itcan operate in a manner similar to other surgical staplers by aligningthe staple driver 404 and the anvil 405 on opposite ends of a staple292, then moving them axially toward one another, by moving either thestaple driver 404 distally, or the anvil 405 proximally, or acombination of the two motions. This relative movement compresses thestaple leg 399 in between the anvil 405 and the staple driver 404 anddeforms it to hold the anastomosis together. An alternative mechanisminvolves rotating the anvil 405 with respect to the staple driver 404and the anastomosis device 390 like a wiper to sequentially bend overthe distal ends 398 of the staples 392, as shown in FIG. 31F. The stapledriver 404 may be equipped with a gripping means for holding thefastening flange 391 to prevent any resultant torque on the flange 391from being transferred to the delicate vascular tissues. Alternatively,the olive-shaped centering element 409 or balloon could have sufficientbearing surface that the delicate vascular tissues do not suffer anysignificant damage. An alternative embodiment would have two or morewiper anvil elements 405 spaced symmetrically about the axis of theshaft 408, so that opposing staples 392 are bent simultaneously,reducing the net torque applied to the centering element 409 and thetissues.

FIG. 32A shows another variation of the anastomosis device of FIG. 31A.This variation of the anastomosis device 410 uses preformed spring-likefastening staples 411. As in the previously described device, theanastomosis device 410 includes a fastening flange 412 with a centralorifice 413 of sufficient size to accommodate the exterior diameter ofthe graft vessel 254. A plurality of preformed fastening staples 411 arearranged around the periphery of the fastening flange 412. Preferably,the staples 411 are preloaded into premade axial holes 414 through thefastening flange 412. The staples 411 should be made of a highlyresilient biocompatible spring material, such as spring-temperedstainless steel or titanium alloys. Superelastic materials, such asnickel-titanium alloys, can also be used for forming the spring-likestaples. Information about the composition and treatment of superelasticmetal alloys useful in the manufacture of the spring like staples can befound in U.S. Pat. No. 4,665,906, entitled Medical Devices IncorporatingSIM Alloy Elements, the entire disclosure of which is herebyincorporated by reference. Two alternate forms for the spring-likestaples 411, 420 are shown in FIGS. 32B and 32C. FIG. 32B shows a singlestaple 411 which has one attachment leg 415. The distal end 416 of theattachment leg 415 is sharpened to easily pierce the blood vessel walls.A distal portion 417 of the attachment leg 415 is bent at an acute anglewith respect to a central portion 418 of the leg 415. Similarly, aproximal portion 419 of the leg 415 is bent at an acute angle withrespect to the central portion 418. The proximal portion 419 and thedistal portion 417 of the staple 411 can be angled in the same directionwith respect to the central portion 418 to make a C-shaped staple, asshown in FIG. 32B, or the proximal 419 and distal 417 portions can beangled in opposite directions to create a Z-shaped staple. FIG. 32Cshows a double staple 420 which has two parallel attachment legs 415.The distal end 415 of each attachment leg 415 is sharpened to easilypierce the blood vessel walls. The distal portions 417 of the attachmentlegs 415 are bent at an acute angle with respect to the central portions418 of the legs 415. The proximal portions 419 of the legs 415 are alsobent at an acute angle with respect to the central portions 418. Theproximal portions 419 of the attachment legs 415 are linked together bya crossbar 421. The double staple 420 has an advantage in that thecrossbar 421 linking the two attachment legs 415 keeps the staple 420aligned within the fastening flange 412. When using double staples 420with the fastening flange 412, the axial holes 414 through the flange412 should be made as pairs of holes 414 spaced apart by approximatelythe length of the crossbar 421 of the staple 420. Similar to the singlestaple 411 of FIG. 32B, the double staple 420 can be made with theproximal portions 419 and the distal portions 417 of the attachment legs415 angled in the same direction with respect to the central portions418 to make a C-shaped staple, when viewed from the side, or theproximal 419 and distal 417 portions can be angled in oppositedirections to create a Z-shaped staple as shown in FIG. 32C.

The operation of either staple version can be understood from thesequence of drawings in FIGS. 32D, 32E, and 32F. The followingoperational description using the single staple 411 of FIG. 32B is,therefore equally applicable to the double staple 420 of FIG. 32C. Thestaples 411 are preferably preloaded into the fastening flange 412 sothat the distal bend 427 of the staple legs 415 is captured within andstraightened by the hole 414 through the flange 412. The resilience ofthe spring material prevents the staple legs 415 from taking a permanentset when they are straightened out to load them into the holes 414 inthe flange 412.

If a superelastic nickel-titanium alloy is used for the spring-likestaples 411, then the shape-memory property of the alloy can be used tofacilitate loading the staples 411 into the flange 412. To do this, thestaple 411 would first be annealed in the desired shape for the finalstaple. Then, the staple 411 would be plastically deformed below itstransition temperature to straighten out the distal bend 427. Thestraightened staples 411 are easily inserted into the holes 414 in theflange 412. Finally, the staples 411 are heated above their shape-memorytransition temperature to make them resume their annealed shape.Preferably, the transition temperature is below body temperature so thatthe alloy of the staple 411 is in its martensitic or superelastic phasewhen the staple 411 is deployed within the body. Since the distal bend427 is captured within the hole 414 in the flange 412, it is heldstraight until the staple 411 is deployed in the following steps.

The free end 259 of the graft vessel 254 is everted over the distalsurface 422 of the fastening flange 412, as shown in FIG. 32D, and thedevice 410 is aligned with an opening 267 that has been previously madein the target vessel wall 255. To help align the central orifice 413 ofthe flange 412 with the opening 267 in the target vessel 255, analignment device 423 can be inserted through the lumen 249 of the graftvessel 254 from the opposite end of the graft. The alignment device 423has a narrow, elongated shaft 424 which fits through the lumen 249 ofthe graft vessel 254 and an atraumatic centering element 425, such as aninflatable centering balloon on the distal end of the shaft 424. Thecentering element 425 serves to align the central orifice 413 of theflange 412 and the graft vessel lumen 249 with the opening 267 in thewall of the graft vessel 255. The alignment device 425 can also be usedto apply a mild amount of traction on the target vessel wall 255 tobetter approximate the everted end 259 of the graft vessel 254 and thetarget vessel 255 when making the anastomosis. Alternatively, thecentering element 425 could be replaced with a vessel punch introducedthrough the graft vessel lumen 249, as in the embodiments described inconnection with FIGS. 2-5.

Once the everted end 259 of the graft vessel 254 and the target vessel255 have been properly approximated, the staple driver 426 is advanceddistally, as shown in FIG. 32E. The distal ends 416 of the staples 411pierce the everted graft vessel wall 259 and the target vessel wall 255and the distal portion 417 of the attachment legs 415 traverses thevessel walls in a linear path. As the distal bend 427 of the attachmentlegs 415 exit the hole 414 in the fastening flange 412, the distalportions 417 begin to resume their acute angle bend. By the time thestaple driver 426 reaches its most distal position, the distal bend 427of the attachment legs 415 is fully reconstituted within the lumen 256of the target vessel 255. When the staple driver 426 is withdrawn, thespring action of the proximal bend 428 in the attachment legs 415 pullsthe staple 411 back slightly to embed the distal portions 417 of theattachment legs 415 into the interior surface 257 of the target vesselwall 255, as shown in FIG. 32F. The spring action of the staples 411also serves to exert compressive force between the fastening flange 412and the target vessel wall 255 to assure a leak proof and secureattachment.

During the manufacture of the staples 411, the distal bends 427 on thestaple attachment legs 415 can be made with almost any desiredorientation. The distal bends 427 can be oriented to turn the distalportion 417 of the attachment legs 415 toward the opening 267 in thetarget vessel wall 255, as shown in FIG. 32F, or the distal portions 417can be oriented pointing away from the opening 267. Alternatively, thedistal portions 417 can be aligned so that they bend tangentially to theopening 267. The tangential distal portions can be oriented so that theycross one another. Perhaps more advantageously, the tangential distalportions 417 can be oriented so that they all bend in the samedirection, as shown in FIG. 32G, so that a more complete gap-free sealis made all around the periphery of the anastomosis.

FIGS. 33A-33D and 34A-34D show two variations of an anastomosis device430 having a fastening flange 431 and a plurality of S-shaped staplemembers 432 formed from a superelastic metal alloy such as anickel-titanium alloy. The fastening flange 431 has a central orifice433 which is sized to accommodate the exterior diameter of the graftvessel 254. The fastening flange 431 has an annular distal ridge 434 andan annular proximal ridge 435 around its outer surface. There are aplurality of holes 436 arranged in a circle around the periphery of thecentral orifice 433 of the flange 431 passing through the flange 431from the proximal surface to the distal surface 438. Each of the holes436 is sized to slidably receive one of the S-shaped staple members 432.There are a plurality of cylindrical lugs 439 extending from theproximal surface 437 of the flange 431. Preferably, the lugs 439 arearranged in a circle concentric with the central orifice 433 and thereare an equal number of lugs 439 to the number of holes 436 in the flange431 with the lugs 439 spaced equidistant from adjacent holes 436.

The S-shaped superelastic alloy staple members 432 are shown inperspective FIG. 33D. The staple member 432 is formed with a straightcentral segment 440 that is attached to a hook-shaped distal segment 441and a proximal segment 442 which bends at an angle just under 90 degreesfrom the central segment 440 in a plane that is approximately at a rightangle to the plane defined by the hook-shaped distal segment 441. Thedistal tip 443 of the hook-shaped distal segment 441 is sharpened toeasily penetrate the graft vessel wall 254 and the target vessel wall255. FIG. 34D shows a slight variation of the staple member 432 of FIG.33D. This variation differs from the previous one in that the distalsegment 444 is bent at an acute angle to the central segment rather thanbeing a fully formed hook. The S-shaped staples 432 are annealed in thedesired configuration so that they will retain the annealed shape. Theextremely resilient nature of the superelastic alloy allows the staplemembers 432 to be completely straightened without causing plasticdeformation of the staples so that they will return to their annealedshape.

The anastomosis device 430 is prepared for use by passing the graftvessel 254 through the central orifice 433 of the fastening flange 431then everting the distal end 259 of the graft vessel 254 over the distalsurface 437 of the flange 431. A suture 445 can be tied around theeverted end 259 of the graft vessel 254 to secure it to the flange 431.The distal ridge 434 of the flange 431 prevents the tied graft vessel259 from slipping off of the flange 431. Next, the staple members 432are straightened and passed through the holes 436 in the flange 431 fromthe proximal surface 437 to the distal surface 438. The distal curve 441of the staples 432 is restrained in the straightened position by thesliding fit with the holes 436 in the flange 431. When the staples 432emerge from the distal surface 438 of the flange 431, they pierce theeverted wall 259 of the graft vessel 254. At this point the fasteningflange 431 with the everted end 259 of graft vessel 254 attached to itis approximated to the exterior surface 258 of the target vessel 255with the central orifice 433 and the lumen 249 of the graft vessel 254centered on an opening 267 that has been made in the wall of the targetvessel 255. The distal ends 443 of the staple members 432 pass throughthe opening 267 in the target vessel wall 255.

Once the graft vessel 254 and the target vessel 255 are properlyapproximated, an annular staple driver 446 is used to push the staplemembers 432 distally through the holes 436 in the flange 431 so thatthey emerge into the lumen 256 of the target vessel 255. As the distalends 443 of the staple members 431 emerge from the distal surface 438 ofthe flange 431 the distal segments 441 resume their annealed shape. Thehook-shaped distal segments 441 of the staple members 431 in FIG. 33Dcurve back toward the interior surface 257 of the target vessel andpenetrate the target vessel wall 255. The proximal segments 442 of thestaple members 432 are positioned between the lugs 439 on the proximalsurface 437 of the flange 431 to lock the staples 432 from rotating withrespect to the flange 431. FIG. 33C shows a proximal view of theanastomosis device 430 with the staple members 432 deployed. This viewis shown without the graft vessel or the target vessel present for thesake of clarity. As best seen in FIG. 33B, the acute angle of theproximal segment 442 acts like a spring to pull back on the staplemember 432 to help the distal segment 441 to pierce the target vesselwall 255 and to help create compression between the flange 431 and thetarget vessel wall 255 to create a leak proof anastomotic seal betweenthe graft vessel 254 and the target vessel 255.

The deployment of the anastomosis device in FIGS. 34A-34D is essentiallythe same as just described up until the point when the distal ends 444of the staple members 432 begin to emerge into the target vessel lumen256. As the distal ends 443 of the staple members 432 emerge from thedistal surface 438 of the fastening flange 431, they resume their acuteangle bend. Rather than penetrating the target vessel wall 255, thedistal segments 444 of the staple member 432 align themselves flatagainst the interior surface 257 of the target vessel 255 and pressagainst the vessel wall 255, compressively clamping the fastening,flange 431 and the everted end 259 of the graft vessel 254 to the targetvessel wall 255. The acute angle of the proximal segment 442 acts like aspring to pull back on the staple member 432 to keep the distal segment444 snug against the interior surface 257 of the target vessel wall 255.

FIGS. 35A-35F show another variation of an anastomosis device 447 usinga fastening flange 448 and attachment staple 449 combination. Thefastening flange 448 is a cylindrical member with an internal lumen 450large enough to accommodate the external diameter of the graft vessel254. The flange 448 has a distal surface 451 over which the free end 254of the graft vessel 259 may be evened. An annular ridge 452 around theouter surface of the flange 448 at the distal end helps to hold theeverted graft vessel 259 in place and serves as part of a lockingmechanism for the attachment staples 449, as will be described below.The attachment staples 449 are in the form of U-shaped hooks with barbedpoints 453 on their distal tips. Each staple 449 has a proximal portion454 which is slidably received within an axial hole 456 through thecylindrical wall 457 of the fastening flange 448. The proximal end 455of the proximal portion 454 is sharpened for easily piercing the tissueof the graft vessel wall 254. A U-shaped bend 458 connects the proximalportion 454 of the staple 449 to the barbed, pointed distal portion 453.

The anastomosis device 447 is applied by removing the U-shaped staples449 from the flange 448. The end 259 of the graft vessel 254 is passedthrough the internal lumen 450 of the flange 448 until the graft vessel254 extends a short distance from the distal end 459 of the flange 448.Then, the end 259 of the graft vessel 254 is everted back over thedistal end 259 of the flange 448. Once the graft vessel 254 is evertedover the flange 448, the staples 449 are reinserted into the holes 456in the flange 458 by piercing the proximal end 445 through the evertedwall 259 of the graft vessel 254. Marks or other visual indications canbe provided on the side of the cylindrical flange 448 to aid in aligningthe proximal ends 455 of the staples 449 with the holes 456. Theproximal portions 454 of the staples 449 are partially advanced into theflange 448 as shown in FIG. 35B. The U-shaped ends 458 of the staples449 are inserted through an opening 267 in the wall of the target vessel255 which has previously been made using a vessel punch or similarinstrument. Two alternate methods can be used for inserting the staples449 through the opening 267 in the target vessel wall 255. In the firstmethod, shown in FIG. 35C, the U-shaped ends 458 of the staples areextended from the cylindrical flange 448 far enough that they easilydeflect inward toward the center of the opening 267 in the target vesselwall 255 when they contact the edge of the opening 267 so that they canbe simultaneously inserted through the opening 267. In the secondmethod, the U-shaped ends 458 of the staples 449 are rotated, as shownin FIG. 35D, so that the U-shaped ends 458 all fit within a circle thatwill pass through the opening 267 in the target vessel wall 255. Oncethe U-shaped ends 458 of the staples 449 are within the lumen 256 of thetarget vessel 255, the staples 449 can be rotated so that the U-shapedends 458 extend radially outward from the fastening flange 448. Thedistal surface 459 of the cylindrical flange 448 with the everted graftvessel 259 attached to it is approximated to the exterior surface 258 ofthe target vessel 255, then the staples 449 are withdrawn in theproximal direction so that the barbed, pointed distal ends 453 piercethe target vessel wall 255. The distal portion 460 of the staple 449passes through the target vessel 255 wall in a linear path, then piercesthe everted edge 259 of the graft vessel wall 254 a second time. Whenthe barbed end 453 of staples 449 pass the annular ridge 452 on thedistal end 459 of the flange 448 the barbs 453 engage the proximalsurface of the ridge 452, locking the staples 448 in position topermanently attach the anastomotic device 447 in place. The excesslength on the proximal portion 454 of the U-shaped staples 449 may becut off flush with the proximal end 461 of the cylindrical flange 448.Alternatively, the proximal portion 454 of the staple 449 can be bentover at the proximal end 461 of the cylindrical flange 448 for a secondmeans of attachment, then the excess length cut off.

Two alternative versions of the anastomosis device of FIG. 35A, usingdifferent locking means for the U-shaped staples, are shown in FIGS.36A-36C and 37A-37C. FIG. 36A shows an anastomosis device 462 with afastening flange 463 and a plurality of non-barbed U-shaped staples 464and a locking collar 465 for locking the U-shaped staples 464 onto thefastening flange 463. The flange 463 and the staples 464 are applied inmuch the same way as described above for the previous embodiment, byinserting the staples 464 through the opening 267 in the target vessel255 and withdrawing them in the proximal direction so that the distalends 466 of the staples 464 pierce the target vessel wall 255 and emergealongside the outer surface of the fastening flange 463. A lockingcollar 465 is then pressed onto the proximal end 467 of the fasteningflange 463, as shown in FIG. 36B, crimping the distal ends 466 of thestaples 464 and locking them to the flange 463 in the process. Theexcess length of the proximal portion 468 of the staples 464 is cut offflush with the proximal end 467 of the fastening flange 463 to completethe anastomosis, as shown in FIG. 36C.

FIG. 37A shows a second anastomosis fitting 469 with non-barbed U-shapedstaples 470 and a locking collar 471 for locking the U-shaped staplesonto the fastening flange 472 of the fitting 469. The fastening flange472 in this embodiment has a conical surface 473 on the outer surface ofthe flange 472 proximal to the distal rim 474 of the flange 472. Theproximal end 475 of the fastening flange 472 has a series of parallelannular locking ridges 476 around its exterior surface. A locking collar471 has an interior taper 477 which matches the conical taper 473 of thefastening flange 472 and a series of parallel locking ridges 478 on theproximal end. After the flange 472 and the staples 470 have been appliedas described above, the locking collar 471 is pressed onto the flange472, as in FIG. 37B. The distal portion 479 of the U-shaped staple 470is wedged between the mating conical tapers 473, 477. The locking ridges478 of the locking collar 471 engage the locking ridges 476 of theflange 472 lo permanently lock the anastomosis device 469 in place andthe anastomosis is completed by cutting off the proximal portions 480 ofthe staples 470 flush with the proximal end of the flange 475, as shownin FIG. 37C.

The anastomosis fittings of FIGS. 33-37 may also be manufactured usingstaple elements made of a highly elastic material, such as asuperelastic nickel-titanium alloy, so that the staples may be preformedwith U-shaped ends which can be straightened and loaded into the holesin the fastening flange. The staples would be deployed by pushing themout the distal end of the flange so that they pass through the wall ofthe graft vessel into the target vessel, after which, they resume theirU shape within the lumen of the target vessel. The highly elastic stapleelements could be locked onto the fastening flange using any of themethods described in connection with FIGS. 33-37.

FIGS. 38A-38C and 39A-39C show one-piece versions of an anastomosisdevice using a fastening flange and attachment staple combination. FIG.38A shows an anastomosis device 481 that has a fastening flange 482 andintegrally formed staple members 483. The fastening flange 482 is a flatannular ring which may be formed from a flat sheet of a biocompatiblemetal. The staple members 483, which may be formed from the same sheetof metal, attach to the inner diameter 484 of the ring 482 and areinitially bent 90° from the flange 482 so that they extend in the distaldirection, as shown in FIG. 38B. The inner diameter 484 of the flangefits over a tubular inner member 485 of an application tool 486. Thegraft vessel 254 is passed through an inner lumen 487 within the tubularmember 485 and then the end 259 of the graft vessel 254 is everted overthe distal end 488 of the tubular member 485. The application tool 486is used to approximate the end 259 of the graft vessel 254 to an opening267 that has previously been made in the wall of the target vessel 255.A tubular staple driver 489 slides telescopically over the exterior ofthe tubular inner member 485. The fastening flange 482 is moved distallyby sliding the staple driver 489 axially with respect to the innertubular member 485, which forces the sharpened distal ends 490 of theintegral staple legs 483 through the everted wall 259 of the graftvessel 254 and the wall of the target vessel 255. Once the staple legs483 have traversed the graft vessel 254 and target vessel walls 255, thedistal ends 490 of the staple legs 483 are deformed to lock theanastomosis device 481 in place as shown in FIG. 38C.

Different methods can be used for deforming the distal ends 490 of thestaple legs 483 to attach the anastomosis device 481. An articulatinganvil, similar to the one described in FIG. 31A can be inserted throughthe lumen 249 of the graft vessel 254 to work cooperatively with thestaple driver 489 to deform the distal ends 490 of the staple legs 483.Alternatively, the fastening flange 482 and the staple legs 483 can bemade of a spring-like elastic or superelastic alloy and preformed intotheir final desired shape. The inner tubular member 485 of the stapleapplication device 486 seen in FIG. 38B holds the preformed distal bend491 in the staple legs 483 straight until the anastomosis device 481 isdeployed by the staple driver 489. Another alternative is to make theanastomosis device 481 and the staple legs 483 from a shape-memoryalloy, such as a nickel-titanium. The staple legs 483 are annealed intheir final shape. Then, the staple legs 483 are plastically deformedbelow the material's transition temperature to straighten out the distalbends 491. The straightened staple legs 483 are driven through the wallsof the graft vessel 254 and the target vessel 255 and the staple legs483 are heated above their shape-memory transition temperature to makethem resume their annealed shape. The material is preferably chosen sothat the transition temperature is at or near body temperature so thatheating the staple above the transition temperature does not causedamage to the delicate vascular tissues.

FIG. 39A shows an additional anastomosis device 492 that has a fasteningflange 493 and integrally formed staple members 494. The fasteningflange 493 in this case is a cylindrical ring formed from a tube of abiocompatible metal. The staple members 494 are attached to the distaledge of the cylindrical fastening flange 493. Optionally, there are alsoproximal fastening members attached to the proximal edge of thecylindrical fastening flange 493. This variation of the anastomosisdevice can be applied with any of the methods just described inconnection with FIGS. 37A-37C. If the anastomosis device 492 has beenmade of an elastic or superelastic alloy, the optional proximalfastening members 495 can serve as spring members to compress theanastomotic attachment, similar to the proximal portions of thespring-like staples 411. 420 described in connection with FIGS. 32A-32F.

FIGS. 40A-40D show a two-piece version of an anastomosis device 496having a fastening flange and integrally formed staple members. In thiscase, the fastening flange of the device is formed of two concentriccylindrical flange rings 497, 498. A plurality of interlocking staplemembers 499, 500 extend from the distal edges of both cylindrical flangerings 497, 498. Preferably, the staple members 499, 500 are integrallyformed with the cylindrical flange rings 497, 498. The staple members499 of the inner flange ring 497 are angled so that they spiral downwardfrom the ring 497 in a clockwise direction. The staple members 500 ofthe outer flange ring 498 are oppositely angled so that they spiraldownward from the ring 497 in a counterclockwise direction.Corresponding locking features 501, 502 on the inner surface of theouter flange ring 498 and on the outer surface of the inner flange ring497 are capable of locking the two flange rings 498, 497 together in afixed position. Indentations on one flange ring, with correspondingdetents on the other flange ring are one of the many possibilities forthe locking features 501, 502.

The anastomosis device 496 is applied by separately placing first theouter flange ring 498, then the inner flange ring 497 around the distalend 259 of the graft vessel 254. The end 259 of the graft vessel 254 isthen everted and approximated to the exterior wall 258 of the targetvessel 255 surrounding an opening 267 which has been previously made inthe wall, as shown in FIG. 40C. The inner ring 497 is moved distallyalong the graft vessel 497 until the points of the staple members 499contact the everted vessel wall 259. The inner ring 497 is pressed intothe everted graft vessel wall 259 and simultaneously rotated in aclockwise direction, thereby driving the staple members 497 through thegraft vessel wall 259 and the target vessel wall 255. Next, the outerring 498 is moved distally along the graft vessel 254 until it isconcentric with the inner ring 497. Then the outer ring 498 is pressedinto the everted graft vessel wall 259 and simultaneously rotated in acounterclockwise direction, driving the staple members 500 through thegraft vessel wall 259 and the target vessel wall 255. When the lockingfeatures 501 of the outer ring 498 coincide with the locking features502 of the inner ring 497, the outer 498 and inner 497 rings becomelocked together. As the flange rings 497, 498 are rotated in oppositedirections, the staple members 499, 500 of the inner 497 and outer rings498 penetrate the vessel walls in opposite directions as shown in FIG.40C, effectively locking the anastomosis device 496 to the exterior 258of the target vessel 255.

Alternatively, the inner 497 and outer rings 498 of the flange can beapplied simultaneously to the everted end 259 of the graft vessel 254 byarranging the rings 497, 498 concentrically, then pressing the staplemembers 499, 500 into the graft vessel wall 259 while counter-rotatingthe inner 497 and outer 498 rings. This could best be done with aninstrument that holds and rotates the inner 497 and outer 498 ringsmechanically.

FIGS. 41A-41E show another approach to making an anastomosis device 503having a fastening flange 504 and a plurality of individual staplemembers 505. The method of deployment used in this embodiment allows thestaple members 505 to be made of a normally elastic metal alloy, such asspring-tempered stainless steel. The fastening flange 504 in thisembodiment is a tubular element with a central orifice 506 which issurrounded by an inner wall 507, a distal surface 508, and an outer wall509 defining an annular space 510 between the inner 507 and outer walls509. The annular distal surface interconnects the inner 507 and outer509 walls. The annular space 510 is sized to fit the staple members 505prior to deployment, as shown in FIG. 41A. A staple application tool 511has an annular staple driver 512 which fits into the annular space 510within the flange 504. The distal surface 508 and the inner wall 507 ofthe flange 504 is slotted with pairs of L-shaped slots 513 to allowpenetration of the staple members 505 through the distal surface 508.

Alternatively, the flange 504 may have a solid body and the annularspace 510 can be replaced by a series of individual staple slots formedin the body of the flange by a process like electrical dischargemachining. The individual staple slots can each be sized to fit a singlestaple member 505. Each individual staple slot should communicate with asingle slot or a pair of slots in the distal surface 508 of thefastening flange 504 for proper deployment of the staple members 505,depending on whether the staple members are single or double-legstaples. In this case, the annular staple driver 512 of the applicationtool 511 must be replaced with an array of individual staple driverssized to fit into the individual staple slots.

The staple members 505 for this embodiment can be made as J-shaped,single-leg staples 505′ or as U-shaped, double-leg staples 505. Whenviewed from the side, the single 505′ and double-leg staples 505 areboth roughly the shape of an inverted J, as seen in FIG. 41A. Thedouble-leg staples 505 combine two such J-shaped staple legs 514 with acrossbar 515 that connects the proximal ends of the staple legs 514 toform staples 505 that are roughly U-shaped when viewed from the front orfrom the top, as in FIG. 41E. The staple legs 514 are formed with acentral segment 516 that is attached at an acute angle to a proximalsegment 517. A short intermediate segment 518 may be used to connect theproximal segment 517 to the central segment 516 of the staple member505. The proximal end of each of the proximal segments 517 is joined tothe crossbar 515 of the staple member 505. A distal segment 519 isattached to the central segment 516 at an obtuse angle so that it isapproximately parallel to the proximal segment 517. The distal end 520of the distal segment 519 is sharpened to easily penetrate the graftvessel wall 259.

The anastomosis device 503 is prepared by passing the graft vessel 254through the central orifice 506 of the fastening flange 504 and exertingit over the distal surface 508 of the flange 504. As an alternative tothe loop of suture described in previous embodiments of the device, avessel cap 521 may be used to secure the everted graft vessel 259 to thefastening flange 509. The vessel cap 521 is a toroidal ring with anL-shaped cross section that fits around the outer diameter of the distalsurface 508 of the fastening flange 504 and holds the everted end 259 ofthe graft vessel 254 in place.

Next, the fastening flange 504 with the everted end 259 of the graftvessel 254 attached is approximated to the exterior 258 of the targetvessel 255 with the central orifice 506 aligned with an opening 267through the target vessel wall 255, as shown in FIG. 41A. The stapledriver 512 is then advanced in the distal direction to press against theattachment legs 514 of the staple members 505 and force the distal ends520 of the staple members 505 through the slots 513 in the distal end508 of the fastening flange 504 to pierce the graft vessel wall 259 andenter the target vessel lumen 256 through the opening 267 in the targetvessel wall 255, as shown in FIG. 41B. As the staple driver 512 isadvanced further the crossbar 515 of the staple member 505 contacts thedistal wall 508 of the fastening flange 504 and the staple member 505begins to rotate about the point of contact, as shown in FIG. 41C. Thedistal segments 519 of the staple members 505 capture the target vesselwall 255 and pull it tight against the distal surface 508 of thefastening flange 504, as shown in FIG. 41D, to form a leak proofanastomotic seal between the everted graft vessel wall 259 and thetarget vessel 255.

FIGS. 42A-42D illustrate another one-piece embodiment of the anastomosisdevice 522 with a fastening flange 523 and attached staple members 524.Preferably, the anastomosis device 522 is made from a deformablebiocompatible metal, such as a stainless steel alloy, a titanium alloyor a cobalt alloy. If desired a surface coating can be applied to theanastomosis device to improve the biocompatibility or other materialcharacteristics.

In contrast to some of the previously described embodiments, in thisversion of the anastomosis device 522, the fastening flange 523 resideson the interior surface 258, of the target vessel wall 255 when theanastomosis is completed. To avoid any problems with hemolysis,thrombogenesis or foreign body reactions, the total mass of thefastening flange 523 has been reduced to an absolute minimum to reducethe amount of foreign material within the target vessel lumen 256.

The fastening flange 523 is in the form of a wire ring 523 with aninternal diameter which when fully extended is just slightly larger thanthe diameter of the graft vessel 254 and of the opening 267 made in thetarget vessel wall 255. Initially, the wire ring 523 has a rippledwave-like shape to reduce the diameter of the ring 523 so that it willeasily fit through the opening 267 in the target vessel wall 255. Aplurality of staple members 524 extend from the wire ring 523 in theproximal direction. In the illustrative embodiment shown in FIG. 42A,there are nine staple members attached to the wire ring fastening flange523. Other variations of the anastomosis device 522 might typically havefrom four to twelve staple members 524 depending on the size of thevessels to be joined and the security of attachment required in theparticular application. The staple members 524 can be formed integrallywith the wire ring fastening flange 523 or the staple members 524 couldbe attached to the ring 523 by welding or brazing methods. The proximalends 525 of the staple members 524 are sharpened to easily pierce thetarget vessel wall 255 and the graft vessel wall 259. Preferably, theproximal ends 525 of the staple members 524 have barbs 526 to improvethe security of the attachment when the device is deployed.

The anastomosis device 522 is prepared for use by mounting the deviceonto the distal end of a specially adapted application instrument 527,as shown in FIG. 42B. The fastening flange 523 is mounted onto an anvil528 attached to the distal end of the elongated shaft 531 of theapplication instrument 527. The staple members 524 are compressed inwardagainst a conical holder 529 attached to the instrument 527 justproximal to the anvil 528. The staple members 524 are held in thiscompressed position by a cap 530 which is slidably mounted on theelongated shaft 531. The cap 530 moves distally to cover the sharpened,barbed ends 525 of the staple members 524 and to hold them against theconical holder 529. The application instrument 527 is then insertedthrough the lumen 249 of the graft vessel 254. This can be done byinserting the instrument through the graft vessel lumen 249 from theproximal to the distal end of the graft vessel 254, or it can be done bybackloading the elongated shaft 531 of the instrument into the graftvessel lumen 249 from the distal end to the proximal end, whichever ismost convenient in the case. The anvil 528 and holder 529 on the distalend of the application instrument 527 with the anastomosis device 522attached is extended through the opening 267 into the lumen 256 of thetarget vessel 255.

Next, the distal end 259 of the graft vessel wall 254 is everted againstthe exterior surface 258 of the target vessel wall 255 with the graftvessel lumen 249 centered on the opening 267 in the target vessel wall255. The cap 530 is withdrawn from the proximal ends 525 of the staplemembers 524, allowing the staple members 524 to spring outward to theiruncompressed position shown by the phantom lines 524′ in FIG. 42B. Theapplication instrument 527 is then drawn in the proximal direction sothat the staple members 524′ pierce the target vessel wall 255surrounding the opening 267 and the everted end 259 of the graft vessel254.

The application instrument 527 has an annular staple former 532 whichsurrounds the outside of the graft vessel 254. Some slight pressure onthe everted graft vessel wall 259 from the annular staple former 532during the piercing step assists in piercing the staple members 524′through the graft vessel walls 259. Care should be taken not to applytoo much pressure with the staple former 532 at this point because thestaple members 524′ could be prematurely deformed before they have fullytraversed the vessel walls. If desired, an annular surface made of asofter material, such as an elastomer, can be provided on theapplication instrument 527 to back up the vessel walls as the staplemembers 524′ pierce through them.

Once the staple members 524′ have full traversed the target vessel wall255 and the graft vessel wall 259, as shown in FIG. 42C, the stapleformer 532 is brought down with greater force while supporting thefastening flange 523 with the anvil 528. The staple members 524′ aredeformed outward, as shown by the phantom lines 524″, so that thesharpened, barbed ends 525 pierce back through the everted graft vesselwall 259 and into the target vessel wall 255 to form a permanentattachment. To complete the anastomosis, the anvil 528 is withdrawnthrough the graft vessel lumen 249. As the anvil 528 passes through thewire ring fastening flange 523, it straightens out the wave-like ripplesso that the wire ring 523 assumes its full uncompressed diameter, asshown in FIG. 42D. Alternatively, the wire ring fastening flange 523 canbe made of a resilient material so that the flange 523 can be compressedand held in a rippled or folded position until it is released within thetarget vessel lumen 256, whereupon it will resume its full, expandeddiameter. Another alternative construction would be to make theanastomosis device of a shape-memory alloy so that the wire ringfastening flange 523 can be compressed and inserted through the openingin the target vessel 267, whereupon it would be returned to its fullexpanded diameter by heating the device 522 to a temperature above theshape-memory transition temperature.

FIGS. 43A-43B, 44A-44B, and 45A-45E show a complete system for creatingan end-to-side vascular anastomosis using an anastomosis device 533 witha fastening flange 534 and a plurality of staple members 535 made of ahighly resilient or superelastic metal. The system includes a speciallyadapted application instrument 536 for applying the anastomosis device533. FIG. 43A shows a top view of the fastening flange 534 of theanastomosis device 533. FIG. 43B shows the fastening flange 534 of FIG.43A in cross section from the side. The fastening flange 534 isgenerally cylindrical in shape with a central orifice 537 of sufficientdiameter to accommodate the external diameter of the graft vessel 254.The wall 538 of the fastening flange has a plurality of holes 539extending from the proximal surface 540 of the flange to the distalsurface 541 of the flange. Preferably there are an even number of holes539, two for each of the staple members 535, which may number from fourto twelve depending on the size of the vessels to be anastomosed. Theillustrated embodiment has twelve holes 539 to accommodate six staplemembers 535. The holes 539 are preferably angled toward the centralorifice 537 from the proximal end 540 to the distal end 541 so that theyexit the wall 538 of the flange 534 at the juncture of the distalsurface 541 of the flange and the internal surface of the centralorifice 537. In the illustrative embodiment shown in FIGS. 43A and 43Bthe holes 539 are angled at approximately 10 degrees to the longitudinalaxis of the flange 534. Other angles are also possible, from −10 to +20degrees from the longitudinal axis of the flange 534 The fasteningflange 534 has a circumferential notch 542 on the exterior of the flange534 close to the distal end 541 of the flange to aid in attachment ofthe graft vessel wall 254. There is also a circumferential ridge 543around the exterior of the fastening flange 534 proximal to the notch542 to assist in gripping the flange 534 for the operation of theapplication tool 536.

FIGS. 44A and 44B show the staple member 535 of the anastomosis device533 in a front view and a side view. The staple members 535 arepreferably formed from wire made of a highly resilient biocompatiblemetal such as a spring-tempered alloy of stainless steel, titanium, orcobalt, or more preferably of a superelastic metal alloy, such as anickel-titanium alloy. The wire preferably has a diameter between 0.006and 0.025 inches, depending on the stiffness of the metal alloy chosen.Nickel-titanium wire with a diameter of 0.010 to 0.012 inches has beenfound to be very suitable for this application. The staple members 535are roughly an inverted U shape when viewed from the front with twoattachment legs 544 joined together at their proximal ends by a crossbar545, as shown in FIG. 44A. When viewed from the side as in FIG. 44B, thestaple members 535 are roughly J-shaped with the distal ends 546 of theattachment legs 544 curving back toward the proximal end of the staplemember 535. Each of the J-shaped hooks 547 ends in a short straightsection 548 with a sharpened distal end 546 to easily penetrate thegraft vessel 259 and target vessel 255 walls. The staple members 535should be annealed or cold worked in the illustrated configuration,whichever treatment is most appropriate for the metal alloy chosen, sothat the staple member has a permanent elastic memory which makes itreturn to the treated shape.

The holes 539 through the fastening flange 534 are sized so that thereis a close sliding fit between the attachment legs 544 of the staplemembers 535 and the interior of the holes 539. The anastomosis device533 is prepared for use by inserting the two attachment legs 544 of eachstaple member 535 into two adjacent holes 539 in the fastening flange534, until the curved distal portion 547 of the attachment legs 544 areentirely within the holes 539. When inserting the staple members 535,they should be oriented so that the curve of the distal ends 547 of theattachment legs 544 will be biased outward from the central orifice 537of the fastening flange 534 when extended distally from the holes 539 inthe flange 534. Because of the close sliding fit, the interior walls ofthe holes 539 constrain the curved distal ends 547 of the attachmentlegs 544 in a straight position, as shown in FIG. 43B. The straightproximal portion 549 of the staple members 535 extend proximally fromthe proximal end 540 of the fastening flange 534 as shown.

The preparation of the anastomosis device 533 can also be accomplishedusing the shape-memory property of a nickel-titanium alloy. The staplemembers 535 would be formed as shown in FIGS. 44A and 44B and annealedto create a shape-memory. The attachment legs 544 of the staple members535 are then straightened by cold working them below the transitiontemperature of the shape-memory alloy. In the straightened condition,the distal ends 547 of the attachment legs 544 are easily inserted intothe holes 539 in the fastening flange 534. Care must be taken to orientthe staple members 535 so that the curve of the distal ends 547 of theattachment legs 544 will be biased outward from the central orifice 537of the fastening flange 534. Once all of the staple members 535 havebeen inserted into the holes 539 of the fastening flange 534, the entireanastomosis device 533 can be warmed above the transition temperature ofthe shape-memory alloy so that the distal ends 547 of the attachmentlegs 544 will try to return to their curved shape. Being constrained bythe interior walls of the holes 539, the attachment legs 544 will remainstraight, but they will have an elastic memory that will cause them toresume their curved shape when they are released from the confinement ofthe holes 539.

With the anastomosis device 533 thus prepared, it is ready to beinserted into the application instrument 536 which is shown in FIGS.45A-45E. The application instrument 536 consists of two separate, butinteracting, mechanisms, a stapling mechanism 550 and a punchingmechanism 551. The punching mechanism 551 is sized to be slidinglyreceived within an internal lumen 552 of the stapling mechanism 550.Most of the parts of the application instrument 536, unless otherwisespecified, are preferably made of a high-strength. dimensionally stablepolymer material, such as acetal. ABS, HDPE. PTFE, etc. Alternatively,the application instrument 536 could be made from stainless, steel,titanium or other metals, if desired.

The stapling mechanism 550 has a generally cylindrical holder 553 whichhas a proximal end 554 and a distal end 555. An internal lumen 556extends from the proximal end 554 to the distal end 555. The distal end555 of the holder 553 is adapted to hold the fastening flange 534 of theanastomosis device 533. A through hole 557 in the distal end of theholder 553 is sized to be a light press fit around the proximal end 540of the fastening flange 534. A counterbore 558 on the distal end of thethrough hole 557 fits the circumferential ridge 543 of the fasteningflange 534 to axially locate the fastening flange 534 with respect tothe holder 553. A staple driver 559, which is generally tubular inshape, is slidably received within the internal lumen 556 in the holder553. The staple driver 559 has a T-shaped handle 560 attached to itsproximal end for operating the stapling mechanism 550. The proximal endof the staple driver 559 has a short tubular extension 561 with acircumferential groove 562 around the exterior of the tubular extension561. The distal end has an annular staple driving surface 563.

To insert the anastomosis device 533 into the distal end of the staplingmechanism 550, the proximal ends 549 of the staple members 535 must beflexed slightly toward the central axis of the fastening flange 534 sothat they will all fit through the through hole 557 on the distal end ofthe holder 553. Once the proximal ends 549 of the staple members 535have been inserted, the proximal end of the fastening flange 540 isinserted into the through hole 557 with the circumferential ridge 543seated into the counterbore 558.

The stapling mechanism 550 is now ready for attachment of the graftvessel 254 to the fastening flange 534. To begin, the graft vessel 254is passed through the internal lumen 552 of the holder 553 and thestaple driver 559. This can be done by tying a suture around one end ofthe graft vessel 254, passing the suture through the stapling mechanism550 and drawing the graft vessel 254 through. Alternatively, anelongated hook or grasping instrument can be inserted through the lumen552 of the stapling mechanism 550 to draw the graft vessel 254 through.The distal end 259 of the graft vessel 254 is then everted over thedistal end 541 of the fastening flange 534. If desired, a loop of suture564 can be tied around the everted end 259 of the graft vessel 254 atthe location of the circumferential notch or groove 542 to secure thegraft 259 to the fastening flange 534. The proximal end 565 of the graftvessel 254 can also be everted and temporarily attached with a loop ofsuture to the proximal extension 561 of the staple driver 559 to makethe graft vessel 254 easier to handle.

At this point, the vessel punch mechanism 551 should be inserted intothe stapling mechanism 550 through the lumen 249 of the graft vessel254. The vessel punch mechanism 551 consists of a housing 566, a cutter567, an anvil 568, a clamp 569, a clamp knob 570 and a punch knob 571.The housing 566 is generally cylindrical in shape. There are two innerchambers 572, 573 in the housing which are separated by an internal wall574. The distal chamber 572 is sized to have a light press fit over theholder 553 of the stapling mechanism 550. A pair of set screws 575 inthe side wall 576 of the distal chamber 572 are provided to secure thehousing 566 to the holder 553. The side wall 576 of the distal chamber572 has pair of opposing open-ended slots 577 that are sized to fit overthe T-shaped handle 560 of the staple driver 559 and allow the handle560 to move axially within the slots 577. The proximal chamber 573 hasan internal thread 579 that matches an external thread 579 on the clampknob 570. A counterbored hole 580 through the internal wall 574 connectsthe proximal 573 and distal 522 chambers.

The cutter 567 of the vessel punch mechanism 551 is a long slendertubular member which is preferably made of a hardenable alloy ofstainless steel. The distal end 581 of the cutter 567 is slightlyenlarged with respect to the shaft 582 of the cutter 567, and there is acounterbore 583 within the enlarged distal end 581. The distal edge ofthe cutter 567 has a sharp, beveled cutting edge 584. Preferably, atleast the cutting edge 584 of the tubular cutter 567 is hardened. Theproximal end of the cutter shaft 582 has a snug press fit into thecounter hole 580 through the internal wall 574 of the housing 566. Thepunch mechanism 551 also includes a clamp 569. The clamp 569 has a longtubular shaft 585 which is sized to be slidably received within theinternal lumen 586 of the cutter shaft 582. An enlarged head 587 on thedistal end of the shaft 585 is sized to fit within the counterbore 583in the distal end of the cutter 567. The distal end of the enlarged head587 has an annular clamping surface 588. The proximal end of the clampshaft 585 is inserted into the cutter 567 and glued or otherwisefastened to the clamp knob 570 which is threaded into the proximalchamber 573 of the housing 566. The anvil 568 of the punch mechanism 551is preferably made of stainless steel. The anvil 568 has an elongatedshaft 589 that has a sliding fit with the internal lumen 590 of theclamp 569. An enlarged head 591 on the distal end of the shaft 589 issized to fit within the counterbored distal end 583 of the cutter with avery close clearance between the head of the anvil 591 and the cutter567. The proximal end of the shaft 589 is threaded to attach it to thepunch knob 571. The punch knob 571 has a distal extension 592 which isthreaded to fit into a threaded hole 593 on the proximal end of theclamp knob 570.

When the clamp knob 570 is rotated with respect to the housing 566, theclamp 569 is advanced proximally or distally with respect to the cutter567. In its farthest distal position, the clamping surface 588 of theclamp 569 is just distal to the cutting edge 584 of the tubular cutter567. When the punch knob 571 is rotated with respect to the clamp knob570, the anvil 568 is advanced proximally or distally with respect tothe clamp 569. By moving the anvil 568 proximally with respect to theclamp 569 when the clamp is in its farthest distal position. the tissueof the target vessel wall can be clamped between the clamp and theanvil. When the clamp knob 255 and the punch knob 571 are rotated inunison, the anvil 568 and the clamp 569 can be withdrawn into thetubular cutter 567 to effect the cutting action of the punch mechanism551. Preferably the clamp 569, the anvil 568 and the tubular cutter 567are keyed to one another or otherwise rotationally fixed so that theymove axially with respect to one another without relative rotation.

The punch mechanism 551, as it has just been described, is inserted intothe stapling mechanism 550 through the lumen 249 of the graft vessel254. The clamp 569 of the punch mechanism 551 should be advanced to itsfarthest distal position before inserting the punch 551 through thegraft vessel 254 to avoid damaging the interior wall of the graft vessel254 with the cutter 567 as it passes through. The set screws 575 in thehousing 566 of the punch mechanism 551 are screwed into correspondingholes 594 in the holder 553 of the stapling mechanism 550 to secure thetwo interacting mechanisms together. The graft vessel 254 occupies anannular space 595 between the punch mechanism 551 and the interiorsurface of the stapling mechanism 550. Thus assembled, the anastomosissystem, which includes the anastomosis device 533 attached to the graftvessel 254 and the application instrument 536, is prepared to perform anend-to-side anastomosis between the graft vessel 254 and a target vessel255.

The operation of the application instrument 536 is illustrated in FIGS.45A-45E. A slit 596 is made in the wall of the target vessel 255 with ascalpel or other sharp instrument. If it has not been done already, theclamp 569 of the punch mechanism 551 is advanced distally by turning theclamp knob 570 until the clamp surface 588 extends slightly beyond thecutting edge 584 of the cutter 567, and the anvil 568 of the punchmechanism 551 is advanced distally by turning the punch knob 571 untilthe anvil head 591 extends distally from the application instrument 536.The anvil head 591 of the punch mechanism 551 is inserted through theslit 596 into the lumen 256 of the target vessel 255, and the distaledge 541 of the fastening flange 534 with the everted end 259 of thegraft vessel 254 attached is approximated to the exterior surface 258 ofthe target vessel 255, as shown in FIG. 45A. The target vessel wall 255is then clamped by the punch mechanism 551 by turning the punch knob 571to move the anvil head 591 proximally until the target vessel wall 255is firmly gripped between the anvil head 591 and the clamp surface 588,as shown in FIG. 45B. The clamp feature of the punch mechanism 551prevents the cutter 567 from prematurely cutting through the wall of thetarget vessel 255 and it provides a firm support to the target vesselwall 255 for the stapling step which follows.

If the anastomosis system is being used to create a proximal anastomosisbetween a graft vessel and the aorta during a CABG procedure, theclamping feature provides an additional benefit at this point in theprocedure. In order to reduce the crossclamp time that the patient issubjected to, many cardiac surgeons prefer to perform the proximalanastomosis while the patient's heart is still beating. This requiresisolating a portion of the aortic wall with a nonoccluding side-bitingclamp to prevent excessive bleeding from the opening formed in theaorta. This has a number of disadvantages: 1) even a nonoccludingside-biting clamp presents additional resistance to aortic blood flow,possibly reducing cardiac output which may already be low, 2) theside-biting clamp tends to distort the aortic wall, making it harder tocreate a neat anastomosis, 3) conventional side-biting clamps aredifficult to apply in a closed-chest or port-access thoracoscopic CABGprocedure, and 4) side-biting clamps may break atherosclerotic tissueloose from the inner wall of the aorta, possibly causing strokes orother complications. The clamping feature reduces the need for theside-biting clamp by clamping directly to the aortic wall around theslit made by the scalpel for inserting the anvil. This creates afluid-tight seal preventing bleeding through the aortotomy opening, sothat the side-biting clamp can be released and removed from the site. Itis also possible to avoid the need for the side-biting clamp entirely byquickly inserting the anvil head 591 of the punch mechanism 551 andtightening the clamp 569 immediately after creating the aortotomy slitbefore significant blood loss can occur. If the head of the anvil 591were made with a blade or trocar extending from its distal surface, thedevice 536 could pierce and dilate an opening in the aorta wall in thesame motion as inserting the anvil 591 through the opening, potentiallysaving time and blood loss.

In the stapling step, the staple driver 559 is advanced distally bypressing on the T-shaped handle 560, as shown by arrows 597 in FIG. 45C.This causes the distal end 563 of the staple driver 559 to press againstthe crossbars 545 of the staple members 535 and forces the attachmentlegs 544 to exit through the holes 539 in the distal end 541 of thefastening flange 534. As the attachment legs 544 emerge from the holes539, the sharpened distal ends 546 of the attachment legs 544 pierce thegraft vessel wall 259 and the short straight section 548 traverses thegraft vessel wall 259 in a linear path. Optionally, the staples 535 canbe advanced through the graft vessel wall 259 before the graft vessel259 is approximated to the target vessel 255 so that the surgeon canverify that all of the staple attachment legs 544 have properly piercedthe everted graft vessel wall 259. The sharpened distal ends 546 of theattachment legs 544 then pierce the target vessel wall 255. The clampingfeature 569 of the punch mechanism 551 supports the target vessel wall255 and keeps it closely approximated to the everted end 259 of thegraft vessel 254 as the staple members 535 penetrate it. As theattachment legs 544 penetrate the target vessel wall 255, the curvedsections 547 of the attachment legs 544 emerge from the confinement ofthe holes 539 in the fastening flange 534 and the elastic memory of theunrestrained curve causes the attachment legs 544 to take a curved pathoutwardly from the central orifice 537 through the target vessel wall255. The distal ends 547 of the attachment legs 544 resume their Jshape, as shown in FIG. 45C, firmly attaching the fastening flange 534and the everted graft vessel 259 to the exterior surface 258 of thetarget vessel 255.

Once the fastening flange 534 and the graft vessel 254 are attached, anopening 267 is made in the target vessel wall 255 by turning the clampknob 570 and punch knob 571 in unison to withdraw the anvil 568 and theclamp 569, with the target vessel wall 255 gripped between them, intothe tubular cutter 567, as shown in FIG. 45D. This action shears off asmall, circular portion of the target vessel wall 255 to form a fluidcommunication between the lumen 256 of the target vessel 255 and thelumen 249 of the graft vessel 254. To complete the anastomosis, thefastening flange 534 is released from the holder 553 and the punchmechanism 551 and the entire application instrument 536 are withdrawn,as shown in FIG. 45E.

FIGS. 46A-46D illustrate a second embodiment of the anastomosis systemusing an anastomosis device 600 with an inner fastening flange 601, anouter flange 602 and staple members 603 made of a superelasticnickel-titanium alloy. The system includes a stapling mechanism 604 forattaching the anastomosis device 600 to the wall of the target vessel255 through a previously made opening 267. The anastomosis device 600has a fastening flange 605, which is shown in top view in FIG. 46C andin side cross section views in FIGS. 46A and 46B. The fastening flange605 includes a tubular body 606 which has an internal lumen 607 ofsufficient diameter to accommodate the external diameter of the graftvessel 254. Attached to the distal end of the tubular body 606 is aninner flange 601 over which the free end 259 of the graft vessel 254will be everted. On the proximal end 610 of the tubular body 606 arethree radially extending lugs 608, which facilitate grasping theanastomosis device 600 while performing the anastomosis. The exterior ofthe tubular body 606 has an external step 609 so that it is slightlylarger in diameter at its proximal end 610 than at its distal end 611.The interior of the tubular body 606 has an internal step 612 so thatthe internal diameter of the tubular body is slightly smaller at thedistal end 610 than at the proximal end 611. A plurality of holes 613pass through the fastening flange 605 from the internal step 612 to thedistal surface 611 of the inner flange 601. The holes 613 are arrangedin pairs, six pairs in this illustrative example, to accommodate a likenumber of staple members 603.

An outer flange 602 is concentrically located on the tubular body 606.The outer flange 602 is attached to the tubular body 606 by aself-locking ring washer 614 which has inclined lugs 615 which allow thering washer 614 to slide distally with respect to the tubular body 606,but which prevent it from sliding proximally. The ring washer 614 can bemade integrally with the outer flange 602 or a separate sheet metal ringwasher 614 can be attached to the outer flange 602, as illustrated. Theinternal orifice 616 of the ring washer 614 and the outer flange 602 ismade with three wide slots 617 between the inclined lugs 615 to allowthem to be placed onto the tubular body 606 over the lugs 615 whichextend from the proximal end 610 of the tubular body 606. The outerflange 602 has a distal surface 618 which is slightly concave. Theperipheral edge 619 of the outer flange 602 has six notches 620 cut intoit which coincide with the location of the distal ends 621 of the staplemembers 603 after they are deployed, as shown in FIG. 46C.

The staple members 603 are generally an inverted U shape when viewedfrom the front as in FIG. 46D. Two attachment legs 622 are joinedtogether at their proximal ends by a crossbar 623. Viewed from the sideas in FIG. 46B, the staple members are somewhat J-shaped with thesharpened distal ends 624 curving back in the proximal direction. Thestaple members 603 are preferably formed from wire made of a highlyresilient biocompatible metal such as a spring-tempered alloy ofstainless steel, titanium, or cobalt, or more preferably of asuperelastic metal alloy, such as a nickel-titanium alloy.

For clarity only the distal end of the stapling mechanism 604 has beenshown in FIG. 46A. Suitable handle means are provided at the proximalend for actuating the stapling mechanism 604. The stapling mechanism 604has an outer sleeve 625, which is a tubular member having three L-shapedfingers 626 extending from its distal end that grasp the radiallyextending lugs 615 on the proximal end of the tubular body 606 like abayonet connector. The clamp sleeve 627 is a tubular member which slidestelescopically over the exterior of the outer sleeve 625. A staple guide628 resides within the outer sleeve 625. The staple guide 628 is atubular member having a plurality of slots 629, equal to the number ofstaple members 603 in the anastomosis device, extending through the wallfrom the proximal end to the distal end of the guide 628. The slots 629in the guide 628 are sized to fit the staple members 603 therein and toconstrain the J-shaped attachment legs 622 of the staple members 603 ina straight position prior to deployment, as shown in FIG. 46A. Thestaple guide 628 can be made by cutting a plurality of slots 629 throughthe wall of the tubular member with electrical discharge machining, orthe staple guide 628 can be made from two closely fitting concentrictubes by cutting slots like splines in the external surface of the innertube and sliding the outer tube over it to close the slots. The stapledriver 630 is a tubular member which is slidably received within theouter sleeve 625. A plurality of fingers 631 extend from the distal endof the staple driver 630. The fingers 631 of the staple driver 630 aresized to be slidably received within the slots 629 of the staple guide628.

The anastomosis device 600 is prepared by inserting the staple members603 into the slots 629 in the staple guide 628 in the stapling mechanism604. The staple guide 628 holds the staple members 603 in a straightenedposition within the stapling mechanism 604. The fastening flange 605 isinserted into the stapling mechanism 604 and the radially extending lugs608 are grasped by the L-shaped fingers 626 of the outer sleeve 625. Thestaple holes 613 through the tubular body 606 are carefully aligned withthe distal ends 621 of the staple members 603 and the staple driver 630is advanced slightly to start the staple members 603 into the holes 613.The anastomosis device 600 is now prepared to perform an end-to-sideanastomosis between a graft vessel 254 and the wall of a target vessel255 as follows.

To begin, the graft vessel 254 is inserted through the central lumen 607of the fastening flange 605 and the internal lumen 632 of the staplingmechanism 604 by drawing it through with a suture or an elongatedgrasping instrument. The distal end 259 of the graft vessel 254 is theneverted over the inner flange 601 on the distal end 611 of the fasteningflange 605. The inner flange 601 with the everted end 259 of the graftvessel 254 attached is inserted through an opening 267 in the targetvessel wall 255 that has previously been made using an aortic punch orsimilar instrument. The staple driver 630 is advanced distally, causingthe sharpened ends 621 of the staple members 603 to pierce the evertedwall 259 of the graft vessel 254 and enter the lumen 256 of the targetvessel 256. As the staple members 603 emerge from the distal end 611 ofthe fastening flange 605, the attachment legs 622 resume their J-shapedcurve and penetrate the interior surface 257 of the target vessel wall255, as shown in FIG. 46D. Once the staple members 603 are completelydeployed, the clamp sleeve 627 is advanced distally with respect to theouter sleeve 625, which forces the outer flange 602 to move in thedistal direction with respect to the tubular body 606. As the outerflange 602 moves distally, the inner flange 601 and the target vesselwall 255 are pulled into the concave distal surface 618 of the outerflange 602 to form a smooth, hemodynamically efficient connectionbetween the lumen 256 of the target vessel 255 and the lumen 249 of thegraft vessel 254. The stapling mechanism 604 is now removed by rotatingthe outer sleeve 625 to release its grasp on the tubular body 606 andwithdrawing the entire stapling mechanism 604. It should be noted thatthe embodiment of FIG. 46, like the embodiment of FIG. 43, couldoptionally be manufactured without an inner flange 601, whereby theinner wall 257 of the target vessel 255 is supported by the staplemembers 603 themselves.

FIGS. 47A-47B, 48A-48B, and 49A-49C show an anastomosis staple device635 which combines a plurality of precurved inner staple members 636 ofa highly resilient material with a plurality of deformable outerattachment legs 637. FIGS. 47A-47B show a top view and a side crosssection view of the anastomosis staple in an undeployed state. FIGS.47A-47B show a top view and a side cross section view of the anastomosisstaple in a deployed state. FIGS. 49A-49C show the sequence ofoperations for deploying the anastomosis staple device. As shown inFIGS. 47A-47C, the device 635 has a ring-shaped bushing 638 with aninternal diameter 639 of sufficient size to accommodate the exteriordiameter of the graft vessel 254. A plurality of deformable attachmentlegs 637, six in this exemplary embodiment, are attached to the proximalend of the ring-shaped bushing 638. The deformable attachment legs 637are preferably made of a metal which can be plastically deformed andwhich will maintain its final deformed shape, such as stainless steel ora titanium alloy. The attachment legs 637 can be machined integrallywith the ring-shaped bushing 638 as shown, or the attachment legs 637can be made separately, for instance by stamping, electrical dischargemachining or die cutting a ring of attachment legs 637 from sheet metal,and fastening the attachment legs 637 to the ring-shaped bushing 638.The attachment legs 637 are typically 0.012 inches thick, 0.040 incheswide and 0.230 inches long. The thickness and width of the attachmentlegs can vary somewhat depending on the stiffness of the material chosenfor the attachment legs 637. It may be desirable to radius the edges ofthe attachment legs 637 or to make the attachment legs 637 round incross section in order to reduce the potential for initiating cracks ortears in the target vessel wall 255. The length of the attachment legs637 can be varied to accommodate different wall thicknesses of the graftvessels 254 and target vessels 255 to be attached.

The attachment legs 637 are typically formed flat, then bent or stampedinto a curved configuration as shown in FIGS. 47B. The distal portion640 of each attachment leg 637 is curved in a circular arc whose centercoincides approximately with the point of attachment 641 between theattachment leg 637 and the ring-shaped bushing 638. The attachment point641 serves as the bending fulcrum for the attachment legs 637 when theyare deformed during the anastomosis procedure. The intermediate portion642 of the attachment legs 637 can be left relatively straight, or anintermediate curve 642 can be formed in the attachment legs 637, asshown in FIG. 47B. The distal ends 643 of the attachment legs 637 aresharpened so that they will easily penetrate the target vessel walls255.

The ring-shaped bushing 638 has a distal surface 644 over which the end259 of the graft vessel 254 will be everted. The distal end 644 of thering-shaped bushing 638 is flared out slightly to provide a more secureattachment of the everted end 259 of the graft vessel 254 to the bushing638. There are a plurality of axial holes 645 in the wall of thering-shaped bushing 638 which communicate with the distal surface 644 ofthe bushing 638. The holes 645 are sized to have a close slidingclearance with the legs 646 of the inner staple members 636. Preferably,the axial holes 645 are arranged in pairs to accommodate both legs ofU-shaped inner staple members 636. As shown in FIG. 47A, the currentlypreferred embodiment has six pairs of axial holes 645 for six U-shapedinner staple members 636. The axial holes 645 are angled outwardslightly, typically by about 10 degrees, from the central axis of thering-shaped bushing 638. Angling the axial holes 645 outward tends toreduce the distance from the distal surface 644 of the bushing 638 tothe bottom of the curve of the staple members 636 once the staplemembers 636 have been deployed. There are also a plurality of transverseholes 647 through the wall of the ring-shaped bushing 638 to facilitategripping the bushing 638 with the staple application instrument 648.

The staple members 636 are generally an inverted U shape when viewedfrom the front as in FIG. 47A. Two staple legs 646 are joined togetherat their proximal ends by a crossbar 649. Viewed from the side as inFIG. 48B, the deployed staple members 636 are somewhat J-shaped with thesharpened distal ends 650 curving back approximately 180 degrees in theproximal direction. The staple members 636 are preferably formed fromwire made of a highly resilient biocompatible metal such as aspring-tempered alloy of stainless steel, titanium, or cobalt, or morepreferably of a superelastic metal alloy, such as a nickel-titaniumalloy. The anastomosis staple device 635 is prepared for use byinserting the curved distal ends 651 of the J-shaped staples into theaxial holes 645 in the ring-shaped bushing 638. The internal walls ofthe axial holes 645 hold the curved ends 651 of the staple members 636in a straightened position within the ring-shaped bushing 638.

The anastomosis staple of FIGS. 47A-47B and 48A-48B is part of acomplete anastomosis system which includes a specialized stapleapplication instrument 648 for performing the anastomosis procedure. Thestaple application instrument 648 is shown in FIGS. 50A-50B. As seen inFIG. 50B, the instrument 648 has a gripper 652 which is adapted to holdthe ring-shaped bushing 638 of the staple device. The gripper 652 is agenerally tubular member that has a plurality of gripping fingers 653extending axially from its distal end. Each of the gripping fingers 653has an inwardly turned distal tip 654 which is sized to fit into one ofthe transverse holes 647 in the ring-shaped bushing 638. The grippingfingers 653 are spring-biased outward. A combination gripper actuatorand outer attachment leg driver 655 is slidably received on the exteriorof the gripper shaft 656. The actuator/driver 655 is generally tubularin shape, having a lumen 657 with a close sliding fit over the exteriorof the gripper 652 and a radiused annular staple driving surface 658 onits distal end. When the actuator/driver 655 is slid distally over theexterior of the gripping fingers 653, the outwardly biased fingers 653are pressed inward so that they grip the ring-shaped bushing 638 byengaging the transverse holes 647.

An inner staple driver 659 is slidably received within the inner lumen661 of the tubular shaft 656 of the gripper 652. The inner staple driver659 has an annular staple driving surface 660 on its distal end. Theinner staple driver 659 has an internal lumen 662 that can accommodatethe graft vessel 254 during the anastomosis procedure. The gripper 652,the actuator/driver 655 and the inner staple driver 659 are heldtogether by a pair of alignment pins 663 which are threaded into thewall of the actuator/driver 655. The gripper shaft 656 has a pair ofopposing axial slots 664 that allow it to slide axially with respect tothe actuator/driver 655. The inner staple driver 659 has a pair ofopposing L-shaped slots 665 oriented to allow the inner staple driver659 to slide axially with respect to the gripper 652 and theactuator/driver 655. The inner staple driver 659 can be moved to alocked position to prevent premature activation of the inner staples 636by withdrawing it distally and rotating it so that the alignment pins663 enter the L-shaped portion 666 of the slots 665.

In preparation for the anastomosis procedure, the proximal end of thering-shaped bushing 638, with the proximal ends of the inner staples 636extending from it, is inserted into the gripper 652 with the transverseholes 647 aligned with the ends 654 of the gripping fingers 653. Theinner staple driver 659 should be withdrawn to the locked positionbefore the staple device 648 is inserted. The actuator/driver 655 isadvanced distally, causing the ends 654 of the gripping fingers 653 toflex inward and engage the transverse holes 647 in the ring-shapedbushing 638. The actuator driver 655 can be advanced distally until itrests against, but does not deform, the attachment leg 637 of the stapledevice 635.

At this point the graft vessel 254 is passed through the internal lumen662 of the staple applying instrument 648 until a short length of thegraft 254 extends from the distal end of the instrument 635. The end 259of the graft 254 is then everted over the distal surface 644 of thering-shaped bushing 638. If desired, a loop of suture can be tied aroundthe everted end 259 of the graft vessel 254 to secure it to the bushing638. The staple instrument 635, with the everted end 259 of the graftvessel 254 attached, is approximated to the exterior surface 258 of thetarget vessel 255 where an opening 267 in the target vessel wall 255 haspreviously been made with a vessel punch or similar instrument. If theanastomosis is part of a port-access CABG procedure, the instrument 635is inserted into the chest of the patient through an access port made inone of the intercostal spaces.

The ring-shaped bushing 638 is inserted into the opening 267 in thetarget vessel wall 255 to approximate the intimal surface on the evertedend 259 of the graft vessel 254 with the intimal surface 257 of thetarget vessel 255, as shown in FIG. 49A. Preferably, the opening 267 inthe wall of the target vessel 255 is made slightly smaller than theouter diameter of the ring-shaped bushing 638 so that there is somecompression around the bushing 638 which helps to seal the anastomosisagainst leakage. The inner staple driver 659 is rotated to release itfrom the locked position and advanced distally to drive the inner staplemembers 636 through the everted wall 259 of the graft vessel 254. As thestaple members 636 exit the axial holes 645 in the bushing 638, theyresume their J-shaped curve 651 so that they curve back distally andpenetrate the interior surface 257 of the target vessel wall 255, asshown in FIG. 49B. After the inner staple members 636 have beendeployed, a light tension is exerted on the staple applying instrument648 to make sure that the inner staple members 636 are well seated andthe actuator/driver 655 is advanced distally to deform the outerattachment legs 637. The sharpened distal ends 643 of the attachmentlegs 637 penetrate the exterior 258 of the target vessel wall 255 in acircular arc, gathering the tissue and compressing it against theexterior of the ring-shaped bushing 638 and the everted edge 259 of thegraft vessel 254 to form a leak-proof anastomotic seal, as shown in FIG.49C. The actuator/driver 655 is withdrawn in the proximal direction,thereby releasing the ring-shaped bushing 638 from the gripper 652, andthe entire staple applying instrument 648 is withdrawn from theanastomosis site.

FIG. 51 shows an additional feature which can be used with any of theanastomosis devices described above. This feature is a combinationstrain relief and compliance mismatch transition sleeve 667. One of thecurrent theories about long-term patency and the causes of restenosis inbypass grafts proposes that the mismatch in vessel compliance betweenthe target vessels, which include the aorta and the coronary arteries,and the graft vessel, typically a saphenous vein, can contribute to thedevelopment of intimal hyperplasia, stenosis and occlusion in the graftvessel, especially at the anastomosis where the compliance mismatch ismost apparent. Joining a highly compliant vessel, such as a saphenousvein, to a relatively noncompliant vessel, like the aortic wall, placesextra strain on the vessels and on the anastomosis. Another cause formismatched compliance at an anastomosis site is the joining of acompliant blood vessel with a highly noncompliant artificial graftvessel. Additionally, turbulence in the blood flow at the anastomosissite may exacerbate the problem, accelerating the stenosis process. Itis preferable that all of the vessels be equally compliant or at leastthat there is a gradual transition in compliance from one vessel toanother. As such, it would be desirable to provide the anastomosisdevices with a means to create a gradual transition in compliancebetween the vessels at the anastomosis site.

Another concern in anastomosis procedures is to create a gradual curvein the graft vessel leading away from the anastomosis site. This issometimes necessary because the most convenient angle for attaching thegraft vessel to the target vessel does not match the desired path forthe graft vessel away from the anastomosis. For instance, in CABGsurgery the desired path for the graft vessel is often parallel to theascending aorta, however the graft vessel must be joined to theascending aorta at some angle in order to create the anastomosis.Creating a gradual curve leading away from the anastomosis site to avoidkinking or narrowing of the graft vessel lumen is sometimes problematic.This is especially true when the graft vessel is joined at right anglesto the ascending aorta. It would be desirable therefore to provide theanastomosis devices with a reliable means to create a gradual curve inthe graft vessel leading away from the anastomosis site.

The combination strain relief and compliance mismatch transition sleeve667 is a flexible tubular member 668 which can be appended to theproximal end of the anastomosis device 669 to support the graft vessel254 leading away from the anastomosis site. The flexible tubular member668 may have any or all of gradually decreasing stiffness, increasingcompliance and increasing diameter as it extends proximally from theanastomosis device 669. This will give the graft vessel 254 a gradualcurve, a gradual change in its radial compliance, and a gradual changein diameter from the constrained diameter within the anastomosis device669 to an unconstrained diameter some distance from the device 669.

The strain relief sleeve 667 can be made in any one of several possibleconstructions, including braided wire or monofilament, a wire or plasticcoil, a solid polymer tube or a composite construction, such as a wirecoil embedded in a polymer wall. The strain relief sleeve 667 may alsobe made of a soft, stretchy, biocompatible polymer, such aspolyurethane, silicone, or Gortex (expanded PTFE).

FIG. 52 shows a device 670 for isolating a portion of the target vessellumen 256 to facilitate performing an anastomosis using any of thedevices and techniques described herein. The isolation device 670 may beused as an alternative to the side-biting clamp described above for usein the proximal anastomosis procedure during CABG surgery. Theside-biting clamp is used in CABG surgery to isolate a portion of theaortic wall so that the proximal anastomosis can be performed while theheart is still beating without excessive bleeding at the anastomosissite. Placing a side-biting clamp thoracoscopically during port-accessCABG surgery may prove problematic. A perfusion endoaortic clampcatheter 670, as shown in FIG. 52, performs the same functions as theside-biting clamp with a percutaneously placed catheter. The catheter670 has a first doughnut-shaped balloon 671 and a second doughnut-shapedballoon 672 which are interconnected by a large-bore perfusion tube 673.The balloons 671 672 and the perfusion tube 673 are mounted on thedistal end of an elongated catheter shaft 674. The balloons 671, 672 andthe perfusion tube 673 are preferably made of a semi-elasticpolyurethane material so that it can be collapsed for percutaneous entryand so it will resume the appropriate shape when they are deployed. Thecatheter shaft 674 may have a single inflation lumen 675 which connectsto both balloons 671, 672 or separate inflation lumens connected to eachballoon. If desired, the catheter 670 may also be provided with aflushing lumen which connects to a flushing port located on the exteriorof the perfusion tube 673 between the balloons 671, 672 for flushing theanastomosis site 678 with clear saline to improve visibility.

In operation, the balloons 671, 672 and the perfusion tube 673 areintroduced percutaneously into a peripheral artery, such as the femoralartery and advance into the ascending aorta 676, preferably underfluoroscopic visualization. When the surgeon is prepared to make theaortotomy incision to start the proximal anastomosis procedure, thefirst and second balloons 671, 672 are inflated, isolating the portionsof the aortic wall 677 between the two balloons 671, 672 from the bloodflow in the aorta. Blood continues to flow through the large-boreperfusion tube 673, supplying the rest of the body with blood. With theaortic wall 677 isolated, the aortotomy incision can be made at theanastomosis site 678 and the anastomosis completed by any of the methodsdescribed in the specification. After the anastomosis is complete, theballoons 671, 672 are deflated and the catheter is withdrawn from theaorta 676.

This catheter approach has certain advantages over the use of aside-biting clamp. First, it isolates a larger portion of the aorticwall so that the surgeon has more choice in the placement of theanastomotic sites. Second, because it isolates a larger portion of theaortic wall it also allows multiple anastomoses to be made to the aortawithout having to move the clamp. Third, it does not distort the wall ofthe aorta as the side-biting clamp does. This may allow more accurateplacement of the anastomotic sites and more effective attachment of theanastomosis devices and therefore reduced leakage of the anastomoses.

A second, smaller scale version of a similar catheter device 679 isshown in FIG. 53 for isolating a section of a coronary artery 682 whileperforming a distal anastomosis. This device would allow the section ofthe coronary artery 682 close to the anastomosis to be isolated from theblood flow without blocking blood flow to vital myocardium downstream ofthe anastomosis site. The availability of rapid and reliable anastomosisdevices, such as those described herein, could open the door toperforming CABG surgery on patients whose hearts are still beating, withno need at all for cardioplegic arrest. The rapidity of the anastomosisprocedure using these devices will minimize the interference from thewall motion of the beating heart that makes hand sutured anastomosesproblematic. However, two other obstacles remain: 1) excessive bleedingat the anastomotic site when the coronary artery is incised, and 2)temporary ischemia of the myocardial tissue downstream of theanastomosis site. The catheter 679 in FIG. 53 solves both of thesepotential problems. The distal end of the catheter has a distal balloon680 and a proximal balloon 681 separated by a few centimeters distancealong the catheter shaft 683. The balloons 680, 681 may be elasticballoons made of latex, polyurethane or silicone, or they may beinelastic balloons made of polyethylene, polyester or polyamide. Thecatheter shaft 683 may have a single inflation lumen 648 which connectsto both balloons 680, 681 or separate inflation lumens connected to eachballoon. If desired, the catheter 679 may also be provided with aflushing lumen which connects to a flushing port located on the cathetershaft 683 between the balloons 680, 681 for flushing the anastomosissite 690 with clear saline to improve visibility. In addition, thecatheter shaft 683 has a perfusion lumen 685 for blood flow through thecatheter 679. The perfusion lumen 685 has one or more inflow ports 686on the catheter shaft 683 proximal to both of the balloons 680, 681 andat least one outflow port 687 at the end of the catheter 679, distal toboth of the balloons 680, 681.

In operation, the catheter 679 is introduced into the coronary artery682 through a coronary guiding catheter 688 which is preferablyintroduced percutaneously from the femoral or brachial artery. Thedistal balloon 680 is advanced past the stenosis 689 in the artery 682,preferably under fluoroscopic visualization, and placed distal to thedesired anastomosis site 690. The proximal balloon 681 is placedproximal to the desired anastomosis site 690 at a point which may beproximal or distal to the stenosis 689. The inflow ports 686 of theperfusion lumen 685, however, should be located proximal to the stenosis689. The proximal 681 and distal 680 balloons are inflated to isolatethe area between them from the blood flow through the coronary artery682. Blood continues to flow into the artery distal to the catheter 679through the perfusion lumen 685. The distal anastomosis procedure cannow be performed on the isolated section of the coronary artery. Whenthe anastomosis is complete, the balloons 680, 681 are deflated and thecatheter 679 is withdrawn.

A third catheter device 691 is shown in FIG. 54. This catheter device691 is configured to be delivered to the anastomosis site through thelumen 249 of the graft vessel 254 which has a number of potentialadvantages. First, the device 691 can be used without the need for afemoral or brachial artery puncture or a coronary guiding catheter todeliver the catheter 691 into the coronary arteries 682. Second, thecatheter 691 can be deployed under direct or endoscopic visualization bythe surgeon without the need for fluoroscopic imaging. Third, theT-shaped configuration of the catheter 691 can help to facilitateapproximation of the graft vessel 254 and the target vessel 255 duringthe anastomosis procedure.

The catheter 691 has a proximal catheter body 692 connected to aT-shaped distal portion 693. The T-shaped distal portion 693 has twodistal ends 694, 695, each having an inflatable balloon 696, 697 at itsdistal extremity. The balloons 696, 697 are each connected to one ormore inflation lumens 698 that terminate in a luer fitting at theproximal extremity of the proximal catheter body 692. A perfusion lumen699 connects a separate luer fitting at the proximal extremity of theproximal catheter body 692 to the extremities of both distal ends 694,695 of the catheter 691, distal to the inflatable balloons 696, 697.

In operation, the T-shaped distal end 693 of the catheter is passedthrough the lumen 249 of the graft vessel 254 with the balloons 696, 697deflated. An incision 700 is made in the wall of the coronary artery 682or other vessel at the desired anastomosis site and both distal ends694, 695 of catheter 691 are introduced into the coronary artery 682through the incision 700. One distal end 695 of the catheter 691 isdirected upstream of the anastomosis site and the other distal end 694is directed downstream of the anastomosis site. Both of the balloons696, 697 are inflated to isolate the portion of the coronary artery 682between the balloons 696, 697 from the blood flow in the artery. Twomodes of perfusion are possible with the catheter 691. If the upstreamend 695 of the distal portion 693 of the catheter 691 receives enoughblood flow, the blood will pass through the perfusion lumen 699 from theupstream side 695 to the downstream side 694 to perfuse the coronaryartery 682 distal to the anastomosis site 700. If the blood flow isinsufficient because of a severe stenosis or total occlusion upstream ofthe anastomosis site 700, blood and/or cardioplegic fluid can beinjected into the catheter 691 through the luer fitting connected to theperfusion lumen 699 at the proximal end of the catheter 691.

With the anastomosis site 700 isolated from the blood flow, the graftvessel 254 can be approximated to the target vessel with the T-shapedcatheter body 693 providing a guide for the approximation. Theanastomosis can be performed in a blood-free environment using any oneof the devices and methods described above. When the anastomosis iscomplete, the balloons 696, 697 can be deflated and the catheterwithdrawn through the lumen 249 of the graft vessel 254.

The catheter devices described above are not limited in their use toCABG surgery. Either of the catheter devices could easily be modified tobe the appropriate size for use during other bypass operations such asaorto-femoral bypass or femoral-femoral bypass.

Port-Access CABG Procedure

A vascular anastomosis procedure using the devices and methods of thepresent invention will now be described in relation to performing aproximal anastomosis on a free graft during a closed-chest orport-access coronary artery bypass graft surgical procedure.Closed-chest or port-access coronary artery bypass graft (CABG) surgeryis a newly developed procedure designed to reduce the morbidity of CABGsurgery as compared to the standard open-chest CABG procedure. Themorbidity is reduced in the port-access CABG procedure by gaining accessto the heart and the coronary arteries through one or more access portswhich are made in the intercostal spaces of the patient's chest, therebyeliminating the need for a median sternotomy or other gross thoracotomyas is required in open-chest CABG surgery. A port-access coronary arterybypass graft surgical procedure using sutured anastomosis techniques ismore fully described in co-pending patent application Ser. Nos.08/023,778 and 08/281,891, which have been incorporated herein byreference.

To prepare the patient for the port-access CABG procedure, the patientis placed under general anesthesia and cardiopulmonary bypass (CPB) isestablished to support the patient's circulatory system during thesurgical procedure. Preferably, a femoral-to-femoral CPB system is usedto reduce the invasive nature of the procedure. One or more access ports702 are made through the intercostal spaces 703 of the patient's chestby making an incision between the ribs 705 and placing a trocar with acannula 704 through the wall of the chest. The trocar is then withdrawn,leaving the cannula 704 as an access port into the chest cavity.Typically, an endoscope, preferably a thoracoscopic surgical microscope,is placed through one of the access ports to allow direct visualizationof the heart, the ascending aorta and the coronary arteries.

Meanwhile a graft vessel is prepared for creating the bypass graft whichwill redirect blood flow from the ascending aorta to one or more of thecoronary arteries downstream of any blockage caused by atheroscleroticdisease. Vessels which can be used as free grafts in CABG surgeryinclude veins, such as the saphenous vein, arteries, such as one of theinternal mammary arteries or the gastro-epiploic artery, and artificialgrafts, such as Dacron or Goretex (expanded PTFE) grafts. If anautologous graft, such as a vein or an artery, is to be used, the vesselis generally harvested from the patient at this time.

Depending on the preference of the surgeon, the proximal anastomosis,which joins the graft vessel to the aorta, can be performed before orafter the distal anastomosis, which joins the graft vessel to one ormore of the coronary arteries. The distal anastomosis is generallyperformed while the patient's heart is stopped, whereas the proximalanastomosis may be performed with the heart stopped or while the heartis still beating, according to the preferences of the surgeon. To stopthe heart, a special endo-aortic clamping catheter, which is describedin the aforementioned patent application, is inserted into the ascendingaorta via a percutaneous entry or a surgical cutdown into the femoralartery. An endo-aortic clamping balloon on the distal end of thecatheter is inflated in the patient's ascending aorta to block bloodflow in the patient's aorta downstream of the coronary arteries.Cardioplegic solution is immediately infused into the patient's coronaryarteries through a lumen in the catheter to temporarily stop thepatient's heart from beating. Alternatively, the proximal anastomosiscan be performed while the heart is still beating by using a side-bitingclamp or other device to isolate a portion of the aortic wall from theaortic blood circulation. With a portion of the aortic wall isolatedfrom the systemic circulation by either of these methods, the proximalanastomosis can be performed using any of the devices and methodspreviously described herein.

The rapidity and reliability of performing the anastomoses using thedevices and methods of the present invention may, in some instances,allow the entire coronary artery bypass procedure, including theproximal and distal anastomoses to be performed without the need forcardiopulmonary bypass support or cardioplegic arrest of the heart. Thiswould be of even greater benefit to the patient by further decreasingthe morbity from the procedure and reducing the likelihood of sideeffects associated with CPB and cardioplegia. It would also bebeneficial to the surgeon and the hospital by reducing the cost andcomplexity of the CABG procedure.

By way of example, the proximal anastomosis procedure will now bedescribed using the two-part anastomosis staple device 100 of FIG. 1. Asmall incision 151 is made in the ascending aorta 707 at the anastomosissite 706 under endoscopic visualization. Then, the vessel punchmechanism 120 and the stapling mechanism 119 with the anchor member 101of the anastomosis staple, which have previously been prepared as shownin FIG. 2, are introduced through one of the intercostal access ports702 and positioned at the anastomosis site, as in FIG. 55. The anchormember 101 is attached to the ascending aorta 707 at the anastomosissite 706 according to the procedure in FIGS. 5A-5D, as follows. Theanvil 136 of the vessel punch 120 is inserted though the incision 151 inthe aortic wall 707, and the anchor member 101 is advanced distally sothat the attachment legs 105 penetrate the aortic wall 707. Then, stapledriver 127 is advanced to deform the attachment legs 105 and fasten theanchor member 101 to the exterior wall of the aorta 707. An opening 152is then punched in the aortic wall 707 with the vessel punch 120 and thepunch 120 is removed along with the tissue 153 excised by the punch. Thegraft insertion tool 121 and the graft vessel 148, which has previouslybeen prepared with the coupling member 102 as shown in FIG. 6 byeverting the distal end of the graft vessel 148 over the coupling member102, are then inserted though the access port 702, as shown in FIG. 56,and the graft vessel 148 is attached to the ascending aorta 707 at theanastomosis site 706 by inserting the coupling member 102 into theanchor member 101 as shown in FIGS. 5F-5G.

The bypass operation is then completed by anastomosing the distal end708 of the graft vessel to the coronary artery 709 below the stenosis orocclusion, as shown in FIG. 57. The distal anastomosis can be performedusing suturing techniques or the graft vessel 148 can be joined to thecoronary artery 709 using a second anastomosis staple by following thesteps shown in FIGS. 5A-5C and FIG. 7C, using the embodiment of thegraft insertion tool 122 illustrated in FIGS. 7A-7C.

Alternatively, the proximal and distal anastomoses can be performed inthe reverse order, as is preferred by some cardiac surgeons. In thiscase the distal anastomosis would be performed first, using the graftinsertion tool 121 of FIGS. 6A-6C, followed by the proximal anastomosisperformed using the graft insertion tool 122 of FIGS. 7A-7C. Whenperforming the proximal anastomosis as the second anastomosis on a freegraft, both ends of the graft vessel can be prepared for anastomosis byattaching a coupling member 102 to the proximal and the distal end ofthe graft vessel 148 and inserting the graft vessel 148 into the chestcavity of the patient through one of the access ports 702 afterattaching anchor members 101 to both the aorta 707 and the coronaryartery 709. Each of the coupling members 102 can then be inserted intoits respective anchor member 101 using the appropriate insertion tool121, 122. An alternate technique is to first attach the distal end ofthe graft vessel 148 to a coronary artery 709 using an anastomosisstaple or sutures, according to the preference of the surgeon, then,after verifying the correct length of the graft vessel, drawing theproximal end 710 of the graft vessel 148 out of the chest cavity throughone of the access ports 702. The free proximal end 710 of the graftvessel 148 can be prepared under direct vision by the surgeon by passingthe free end of the graft vessel through the lumen of the couplingmember 102 and everting it over the distal end 115 of the couplingmember 102. The coupling member 102 with the proximal end 710 of thegraft vessel attached can be reinserted into the chest cavity throughthe access port 702 and inserted into an anchor member 101 attached tothe aortic wall 707 using the graft insertion tool 122 of FIGS. 7A-7C.This same technique can be used with the two-piece anastomosis staplefor performing a distal anastomosis on a pedicled graft vessel or forperforming a distal anastomosis on a free graft after the proximalanastomosis has already been made.

The operation of the one-piece anastomosis staples of FIGS. 9, 10, 11 or12 can also be understood in relation to FIGS. 55-57. The graft vessel148 and the one-piece anastomosis staple 163 are prepared as describedabove in relation to FIGS. 13 and 14. A small incision 151 is made inthe ascending aorta 707 with a sharp blade at the intended anastomosissite 706, which has been isolated from the circulation with aside-biting clamp or other isolation device. An elongated punch, whichmay be similar to the vessel punch 120 described in relation to FIGS. 2and 5D above, is inserted through one of the access ports 702 in thepatient's chest. An opening 152 is made in the wall of the ascendingaorta 707 by inserting the anvil of the punch through the incision, thenpressing the actuating plunger to advance the tubular cutter over theanvil. The staple applying tool of FIG. 13 with the graft vessel 148everted over the distal tubular extension 166 of the anastomosis staple163, as shown in FIG. 14, is introduced through an access port 702 andpositioned near the punched hole 152 in the ascending aorta 707 asillustrated in FIG. 55. The flanged end 167 of the distal tubularextension 166 is passed through the hole 152 so that it is in theposition shown in FIG. 10. The wall of the ascending aorta 707 stretchesslightly to allow the flange 167 to pass through the hole 152. Thestaple applying tool 179 is pulled back slightly to make sure the flange167 of the staple 163 engages the interior wall of the aorta 707, thenthe lever 185 of the staple applying tool 179 is pulled to deform theattachment legs 168 of the staple 163 and drive them through the aorticwall 707, as shown in FIG. 10. The lever 185 is released and the stapleapplying tool 179 is rotated to disengage the staple retainer 188 fromthe tabs 170 on the proximal tubular extension 169 of the staple 163.The staple applying tool 179 is withdrawn and the anastomosis iscomplete.

As with the two-piece embodiment of the anastomosis staple, theone-piece anastomosis staple of FIG. 9 can also be used for creating theproximal and/or distal anastomoses on a graft vessel in either order,according to the preference of the surgeon. When performing the secondanastomosis on a free graft or the distal anastomosis on a pedicledgraft, the free end of the graft vessel can be drawn out of the chestcavity through one of the access ports to prepare the end of the graftvessel under direct vision by the surgeon. The graft vessel is preparedby passing the free end of the graft vessel through the lumen of theanastomosis staple and everting it over the distal flange. Theanastomosis staple with the free end of the graft vessel attached can bereinserted into the chest cavity through the access port and attached tothe wall of the target vessel, which may be the ascending aorta or oneof the coronary arteries.

Although the foregoing description focuses on the use of the anastomosissystem in closed-chest CABG surgery, the system is equally applicable toother situations that require vessel anastomosis, including, but notlimited to renal artery bypass grafting, aorto-femoral bypass,femoral-femoral bypass and arterio-venous shunting, such as is commonlyused for dialysis. Surgical anastomoses are also performed for variousreasons on many different tubular organs of the body other than bloodvessels, including the bowel, intestines, stomach and esophagus. Whilethe devices and methods of the present invention are intended primarilyfor vascular anastomoses, some or all of the embodiments could also bemodified for performing end-to-side anastomoses on other tubular organs.Any one of the one or two-piece embodiments of the anastomosis stapledevice can be supplied preattached to a prosthetic graft vessel. Forinstance, the two-piece anastomosis staple device could be supplied in akit, including a natural or artificial graft that is prepared with acoupling member attached to one or both ends and one or two anchormembers for attachment to the target vessel(s). Likewise, the one-pieceanastomosis staple device can be supplied in a procedural kitpreattached to a prosthetic graft vessel. This is equally applicable toartificial graft materials, such PTFE or Dacron grafts, or to naturalbiological graft materials, including allografts of human graft vessels,or xenografts such as bovine or porcine graft vessels, either freshlyharvested, glutaraldehyde treated or cryogenically preserved. Ananastomotic device application instrument, such as those describedabove, could also be supplied in the procedural kit with one of theanastomotic devices already attached to the distal end of theinstrument.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the invention, which is defined by the appendedclaims.

What is claimed is:
 1. A method of forming an anastomosis for placing alumen of a graft vessel in fluid communication with a lumen of a targetvessel, the method comprising: (a) forming an opening in a target vesselwall; (b) passing at least a distal end of an anastomosis device throughthe opening in the target vessel wall, the anastomosis devicecomprising: (i) a fastening flange having a reduced diameter and beingexpandable to an uncompressed diameter; and (ii) a plurality of staplemembers extending from the fastening flange; (c) bringing an end of thegraft vessel proximate to the opening in the target vessel wall; (d)engaging at least one of the graft vessel and the target vessel with theplurality of staple members; and (e) expanding the fastening flange fromthe reduced diameter to the uncompressed diameter.
 2. The method offorming an anastomosis according to claim 1, wherein the staple membersare biased radially outward from a center of the fastening flange, andfurther comprising: (f) constraining the staple members as the distalend of the anastomosis device is passed through the opening in thetarget vessel wall.
 3. The method of forming an anastomosis according toclaim 2, wherein (f) further comprises constraining the staple membersradially inward towards a center of the fastening flange.
 4. The methodof forming an anastomosis according to claim 2, further comprising: (g)allowing the staple members to deflect radially outward after at least adistal end of the anastomosis device passes through the opening in thetarget vessel wall.
 5. The method of forming an anastomosis according toclaim 2, wherein (f) comprises disposing a cap over the ends of thestaple members.
 6. The method of forming an anastomosis according toclaim 5, further comprising: (h) allowing the staple members to deflectradially outward after at least a distal end of the anastomosis devicepasses through the opening in the target vessel wall by axiallydisplacing the cap from the ends of the staple members.
 7. The method offorming an anastomosis according to claim 6, wherein (h) furthercomprises displacing the cap proximally from the ends of the staplemembers.
 8. The method of forming an anastomosis according to claim 2,wherein the anastomosis device further comprises a shape-memory alloy,and (f) comprises deflecting the staple members radially inward whilethe anastomosis device is below the transition temperature of theshape-memory alloy.
 9. The method of forming an anastomosis according toclaim 8, further comprising: (i) allowing the staple members to deflectradially outward after at least a distal end of the anastomosis devicepasses through the opening in the target vessel wall by allowing thetemperature of the anastomosis device to exceed the transitiontemperature of the shape-memory alloy.
 10. The method of forming ananastomosis according to claim 8, wherein the transition temperature ofthe shape-memory alloy is below body temperature.
 11. The method offorming an anastomosis according to claim 2, wherein the anastomosisdevice further comprises a surface coating on at least a portion of thesurface of the anastomosis device.
 12. The method of forming ananastomosis according to claim 11, wherein the surface coating improvesthe biocompatability of the anastomosis device or reduces thrombosis.13. The method of forming an anastomosis according to claim 2, whereinthe anastomosis device further comprises one of a stainless steel alloy,a titanium alloy, and a cobalt alloy.